MEDICAL LABORATORY TECHNICIAN ASCP-MLT Practice Exam

1. Each of the drugs/drug classes listed above have been known to cause drug-induced hemolytic anemia, although cephalosporins are the MOST COMMON cause. Cephalosporins can cause drug-induced hemolytic anemia when a patient produces antibodies to the particular cephalosporin drug in the presence of red blood cells. The drugs can alter the membrane appearance of the red blood cells, causing the body to mistake them as foreign. Complement becomes activated due to these antibodies; red cells are then destroyed causing hemolytic anemia. Dark urine, caused by intravascular hemolysis, is one of the most common symptoms associated with this condition.

Which one of the following drugs/drug classes is the MOST COMMON cause of drug-induced hemolytic anemia?

2. The molecular weight of a hapten is by itself not sufficient to elicit an antibody response alone, but requires a protein to do so.

A hapten is only antigenic when it is coupled with which of the following:

3. To make a 1 : 10 dilution, 270 µL of diluent should be added to 30 µL of sample, .

A spinal fluid that is slightly hazy is briefly examined microscopically. The technologist performing the count decides to make a 1:10 dilution using 30 µL of sample.

What volume of diluent should be used?

4. What is the best description of the purpose of the Commission on Office Laboratory Accreditation (COLA) pertaining to the clinical laboratory?

5. PCT usually rises within 3-6 hours of infection. CRP also increases rapidly following infection, but is not as specific for infection as PCT. A rise in CRP could also occur with SIRS. Lactic acid is usually used to detect and monitor impaired circulation and tissue oxygenation in critically ill patients.

Chemistry

Of the three laboratory tests that are listed, which has proven to be most effective for early differentiation of systemic inflammatory response syndrome (SIRS) from sepsis due to its increase following infection and higher specificity?

6. Most researchers believe that the small size and increased density of LDL molecules found in atherogenic dyslipidemia enable the molecules to more easily invade the endothelium and arterial wall of vessels.

Why are small dense LDL molecules more atherogenic?

7. Molarity x Molecular Weight x Volume = Grams

Molecular Weight (aka Formula Weight) =

2(1) + 32 + 4(16) = 98

So, 4 x 98 x 0.2L = 78.4g

What weight of H2SO4 is contained in 200 ml of a 4 molar H2SO4 solution? (Atomic weight: H= 1; S = 32; 0 = 16)

8. Shigella and Salmonella are not found as normal flora in the gastrointestinal tract.

Which of the following are not considered normal flora of the gastrointestinal tract:

9. The identification of the crystals depicted in this image are triple phosphate crystals. Triple phosphate crystals may be normal but are usually associated with alkaline urine. These colorless crystals have a characteristic "coffin lid" appearance.





What is the identification of these crystals seen in urine with an alkaline pH?

10. Though automated extraction machines have many benefits over manual methods the costs are high and generally require a high throughput of samples in order to justify the costs.

Automated extraction has many benefits over the traditional manual methods. The most important benefit is that the nucleic acid isolated is constantly consistent. There is a reduced amount of manipulation with dramatically decreases the chance of cross contamination. Also, automated extraction machines are considered moderate complexity

and can be performed by a wider variety of laboratory professionals.

All of the following are considered benefits of automated isolation and extraction equipment

EXCEPT:

11. Extension (Creating the complementary strand to produce new double stranded DNA.)

What is the first step of the PCR reaction?

12. The risk of HbS polymerization is enhanced by a low (acid) pH, a state of dehydration, and increased levels of 2,3-DPG. Increased temperature (above 37°C) also adds to the risk.

Hematology

Which group of conditions INCREASES the risk of HbS polymerization?

13. The governmental agency that oversees public health care matters in the United States is:

14. Duffy antigens are rendered inactive by enzyme treatments since the enzyme will remove the sialic acid from the RBC membrane. This process destroys: M, N, S, s, and Duffy antigens. The process enhances the reactions for Rh, Kidd, Lewis, I, and P antigens.

When performing an antibody panel, which one of the following antigens will be rendered inactive by enzyme treatment?

15. 2(2)2s = reject when 2 consecutive control measurements exceed the same mean plus 2s or the same mean minus 2s control limit.

Violation of this Westgard rule is usually caused by a systematic error.

Laboratory Operations

Which of the following describes the Westgard multirule 2(2)S?

16. India ink can aid in the visualization of the polysacchride capsules of yeast such as Cryptococcus neoformans.

Micro

India Ink is used to:

17. Drawing a lavendar stopper tube before an SST tube can cause a falsely:

Question options:

18. Phase of reactivity is primarily at immediate spin (4+) and reactions get weaker at AHG (w+). There is no specific pattern of reactivity and the auto control is negative which rules out an autoantibody. This is a strong cold antibody which is still slightly present after incubation and washing.

Activation and binding of the antibody takes place at room temperature or colder. Eliminating this phase will prevent the antibody from binding. Cold antibodies usually are more of a nuisance to blood bankers and are not clinically significant.

When performing an antibody screen, both the screen cells are 4+ at immediate spin and W+ at AHG. The antibody panel shows 4+ reactions at immediate spin and W+ reactions at AHG and there is no specific match to the reaction pattern. The auto control is negative.

What would be a logical next step?

19. First, determine the number of WBC's from the hemocytometer as follows:

WBC count = (dilution ratio x # of cells counted x 10) / (# mm2 area counted)

Then: WBC count = (20 x 100 x 10) / (8) = 2500 WBC/mm3 (or 2500 WBC/uL or 2.5 x 103 WBC/uL)

Next, to find the WBC count per liter, multiply the WBC count/uL by the number of uL/L (there are 106 uL/L)

So: (2.5 x 103 WBC/uL) x (106 uL/L) = 2.5 x 109 WBC/L

Hematology

A 1:20 dilution is made for a manual WBC count. The four corner squares on both sides of a hemocytometer are counted. A TOTAL of 100 cells are counted in that area.

What is the white blood cell count in terms of a liter (? x 10^9/L)?

20. Which of the following CD markers is NOT present on a normal mature T cell?

21. Though it may not be required, TDM should still be used to confirm adequate dosing.

Genotyping does not make TDM redundant.

A PM will metabolize the drug more slowly and therefore will need lower doses. CYP2D6 metabolizes many different drugs; it is not associated with just one class of drugs. Anytime a drug is taken that competes for the same metabolizing enzyme as another drug, there is potential for the concentrations of both drugs to be increased.

A patient has been characterized as a CYP2D6 poor metabolizer (PM) after genotyping.

Which of the following statements is not true?

22. Transfusion of red cells of any ABO type other than O to a group O patient is of course likely to cause a hemolytic transfusion reaction.

Which of the following types of packed RBCs could be transfused to a group O patient:

23. Since cimetidine inhibits CYP2D6, less amphetamine will probably need to be given since it will not be able to be metabolized as readily.

Most drug interactions are like this: one drug inhibits or competes with the same CYP450 as another drug. The end result is that higher concentrations of one, or both, drugs are present, leading to potential toxicity.

A patient is taking cimetidine for a stomach ulcer. This drug inhibits CYP2D6. The patient is now prescribed amphetamine for narcolepsy. Amphetamine is metabolized by CYP2D6.

What would you predict?

24. Which of the following tubes produces a serum sample?

Question options:

25. Insulin is the hormone that is mainly responsible for the entry of glucose into the cell for energy production

Glucagon and epinephrine promote glycogenolysis, conversion of glycogen to glucose, which increases plasma glucose. Cortisol, along with glucagon, increases gluconeogenesis, formation of glucose from noncarbohydrates, which also raises plasma glucose concentration.

Chemistry

Which of the following hormones is mainly responsible for the entry of glucose into the cell for energy production?

26. Basophilic stippling is the term used to describe red blood cells that contain tiny particles of RNA within their cytoplasm. Basophilic stippling is associated with many conditions, but is strongly associated with lead poisoning.

Multiple small, dark blue particles scattered throughout the cytoplasm of erythrocytes is/are called:

27. This is the lens power of the scanning objective lens.

28. Measuring the turnaround times of troponin tests from the emergency department would provide valuable information. This data represents circumstances in which patient safety may be compromised if results are delayed and treatment is not started as soon as possible.

A laboratory manager wants to evaluate the timeliness of patient services in order to prevent medical errors caused by delay in treatment. Measuring the turnaround time for which of these analytes would provide the most valuable information?

29. Cryoglobulin testing can be used to:

30. A patient has a WBC count of 4,000/mm3, a platelet estimation with 3 bizarre platelets/oil

immersion field, hemoglobin, hematocrit, red cell count and indice values are within normal limits. Blue-staining inclusions are seen in the cytoplasm of many neutrophils. These inclusions fit the description of:

31. Bacterial contamination of platelets is most likely because they are stored at room temperature.

Bacterial contamination is MOST likely in which of the following blood products?

32. Rule-out is a process by which antibodies are identified as being unlikely in a given sample because of the absence of an expected antigen-antibody reaction. In other words, the absence of a reaction is noted with a cell that is positive for the corresponding antigen.

Although rule-out procedures may vary somewhat from institution to institution, the following general principles apply:

Non-reactive cells are selected for rule-out. To be classified as non-reactive, a cell must NOT have reacted at any phase of testing in a given panel or screen.

Using the logic that if the rule-out cell is positive for a given antigen, it should have reacted with the corresponding antibody, you can rule-out antibodies that correspond to antigen positive cells.

To increase the probability that rule-out will not mistakenly eliminate a weakly-reacting antibody that exhibits dosage*, use only cells that are homozygous for the corresponding antigen for those systems that generally show dosage. Generally these include: C, c, E, e, Fya, Fyb, Jka, Jkb, M, N, S, and s.

In this case, it is only possible to rule out on screening cell 2 since it demonstrates a negative reaction with the patient serum. Anti-C cannot be ruled out since the C antigen is heterozygous on screening cell 2 with c. Anti-Fya cannot be ruled out since this antigen is not present on screening cell 2. Anti-M and anti-Jka can be ruled out since the antigens are homozyous while demonstrating a negative reaction on screening cell 2.

Rule-out, while very useful, can lead to error. Ruling out an antibody should be combined with other supporting data to increase confidence in the solution; the more data collected, the higher the probability that the final solution is correct.

*Dosage means that there are two "doses" of the same antigen present on the red cells . Antibodies that exhibit dosage react more strongly with homozygous cells (e.g., Jka Jka) than with heterozygous cells (e.g., Jka Jkb) .

Based on the phenotype of the RBC screening cells, and patient results shown on the right, which of the following antibodies CANNOT be ruled out?

33. Macroamylasemia can be diagnosed by measuring amylase levels in the urine and serum. In patients with macroamylasemia, there will be high levels of amylase in the serum. However, macroamylasemia can look similar to acute pancreatitis, which also causes high levels of amylase in the blood. To help differentiate, we measure amylase levels in the urine. Urine levels of amylase are low in people with macroamylasemia, but high in patients with pancreatitis.

The results which would be MOST consistent with macro-amylasemia are?

34. Serum ferritin is a good indicator of iron deficiency. However, it acts like an acute phase reactant, being elevated in a large number of conditions. Patients who have iron deficiency as well as another condition that elevates serum ferritin levels may therefore have normal or even elevated serum ferritin levels.

Which one of the following statements about serum ferritin are true:

35. Use Perls' Prussian blue stain.

36. The FTA-ABS is used to confirm that a positive non-treponemal test like RPR is not the result of a biological false positive, which occur in about 1 to 10 percent of the population.

A positive RPR test and a negative FTA-ABS test is most likely the result of:

37. Porphobilinogen

38. Western blot analysis is frequently utilized as the confirmatory method of HIV detection.

Which of the following assays is routinely used for confirmation of HIV infections:

39. FFP that has been thawed at 30 - 37oC and maintained at 1 - 6oC must be transfused within 24 hours. In contrast, "Thawed Plasma" can be used for up to 5 days as a replacement therapy for patients requiring stable clotting factors. Keep in mind that these are two different component types and you are asked about FFP.

Blood Bank

FFP that has been thawed at 30 - 37oC and maintained at 1 - 6oC must be transfused within ___________ after it has been thawed.

40. Hematology

What is Coombs sera comprised of:

41. Orthomyxovirus

42. What additional fraction would be seen if plasma rather than serum was subjected to electrophoresis:

43. To prevent blood from clotting the specimen must be:

44. Plasma concentrations of creatinine are used to assess renal function. Creatinine clearance is based on the serum creatinine level and is used to measure glomerular filtration rate, or GFR.

An increased serum level of which of the following analytes is MOST commonly associated with decreased glomerular filtration?

45. Using the formula on the right,





Cells/µL = 370 x 100 / 18 x 0.1

Cells/µL = 37000 / 1.8

Cells/µL = 20556 or 2.06 x 104

A sample of cerebrospinal fluid is diluted 1:100; the standard 9 squares of a hemocytometer are counted on each side for a total of 18 large squares.

Side 1-- 186 nucleated cells counted

Side 2-- 184 nucleated cells counted

total nucleated cells = 370

Using the standard hemocytometer formula shown on the right, what is the nucleated cell count per microliter (µL)?

46. As magnification INCREASES, the field of view will...

47. Clostridium difficile is a gram-positive, spore-forming bacilli. The remaining organisms will all stain gram-negative on direct smear or smears made from culture.

Which of the following organisms are gram-positive?

48. Delayed hemolytic transfusion reactions (DHTR) usually occur within which time period?

49. Spirochetes such as Borrelia and Treponemes are best visualized using darkfield microscopy. Borrelia, which causes Relapsing fever, can be visualized under darkfield microscopy of wet preps of peripheral blood. Treponema can be visualized by darkfield microscopy of early primary lesions, and aspirates of affected lymph nodes.

Which of the following organisms is best visualized by use of a darkfield microscope:

50. The characteristic that distinguishes vancomycin-resistant Enterococcus faecium and Enterococcus faecalis from other Enterococcus species is their lack of motility.

Enterococci are all catalase-negative. Growth on bile esculin agar and in 6.5% salt broth are two characteristics that have commonly been used to identify Enterococcus to the genus level. A positive esculin in combination with a positive PYR reaction is another approach to presumptive identification.

Which one of these characteristics distinguishes vancomycin-resistant Enterococcus faecium and Enterococcus faecalis from other Enterococcus species?

51. The liver is the primary target organ for the Hepatitis B virus (HBV). The inflammation caused by HBV can result in permanent liver damage, including cirrhosis, liver failure, and even hepatocellular carcinoma.

What is the primary target of the Hepatitis B virus?

52. In DIC, or disseminated intravascular coagulation, the prothrombin time is increased due to the consumption of the coagulation factors due to the tiny clots forming throughout the vasculature. This is also the reason that the fibrinogen levels and platelet levels are decreased. Finally FDP, or fibrin degredation products, are increased due to the formation and subsequent dissolving of many tiny clots in the vasculature. The FDPs are the pieces of fibrin that are left after the fibrinolytic processes take place.

Which of the following laboratory results would be seen in a patient with acute Disseminated Intravascular Coagulation (DIC)?

53. Hypochromia can best be described as:

54. The activities conducted in a laboratory with a certificate of waiver include:

55. Howell-Jolly bodies are composed of DNA, usually left from the nucleus, that appears as a round, dark-staining inclusion in the cytoplasm of red blood cells. Howell-Jolly bodies can be found in various conditions including splenectomy and anemia.

Remnants of erythrocyte nuclei, nuclear fragments, or aggregates of chromosomes are called:

56. Which area of the laboratory can analyze a patient sample and be able to predict their risk of developing a disease?

57. All of the following tubes contain separation gel except:

Question options:

58. Caffeine benzoate solution is used to split the unconjugated bilirubin protein complex releasing the bilirubin so that it can react with diazotised sulphanilic acid. The tartrate buffer creates an alkaline solution and converts the red acid bilirubin to a green coloured compound which can be measured spectrophotometrically.

Which substance is used in the Jendrassik-Grof method to accelerate the reaction of unconjugated bilirubin with the diazo reagent?

59. Provide the equivalent measurement for one pint.

60. The Needlestick Safety and Prevention Act requires employers to:

61. Fibers can be mistaken for casts on occasion, especially hyaline casts. Fibers, however, are usually thinner and appear less uniform in structure than casts do.

Urinalysis & Other Body Fluids

Which of the following artifacts may be mistaken for casts?

62. HbA1C is the recommended test for monitoring diabetic carbohydrate management. Microalbuminuria, low concentrations of urinary albumin, is measured to detect early renal impairment, at a stage where it is reversible with treatment.

What is the role of microalbuminuria testing?

63. Which of the following legislation was developed to protect the privacy of all patient information in the health care?

64. Parathyroid hormone regulates serum calcium by acting on bone, kidney, and intestines while regulating phosphate by stimulating the intestines and the kidneys, enhancing absorption and reabsorption respectively.

Chem

The parathyroid hormone is important in the regulation of:

65. Blood Bank; Immunology

Which of the following best describes the primary function of antibodies:

66. Coumarin derivatives inhibit the vitamin K dependent Factors (II, VII, X) which can be measured with the PT and monitored frequently with the INR assay.

Hematology

Warfarin-based (coumarin derivative) oral anti-coagulant therapy is commonly monitored with :

67. The structures involved in the production of semen include the prostate, the seminal vesicles, and the bulbourethral gland, along with the testes and epididymis.

Semen is produced as a combination of secretions from the different regions of the male reproductive tract. Each fraction differs in chemical composition and function.

Spermatozoa are produced in the testes. They mature in the epididymis. The testes also produce testosterone and inhibin.

Fluid from the seminal vesicles accounts for approximately 70% of semen volume. The seminal vesicles are the source of fructose in semen. Fructose is used by the spermatozoa as an energy source.

The prostate gland supplies about 20% of the volume of semen. Its fluids include acid phosphatase and proteolytic enzymes that lead to coagulation and subsequent liquefaction of semen. The prostate also contains most of the IgA found in semen.

The bulbourethral gland produces mucoproteins that make up about 5% of the volume of semen.

The pituitary gland is not directly involved in the production of semen; instead hormones are released which stimulate the production of sperm. The urethra is not involved in the production of semen.

Which of the following are directly involved in the production of semen?

68. Public health guidelines recommend that manipulation of samples for influenza testing be done inside a safety cabinet. Safety goggles could be worn if the specimen or procedure may be prone to splashes or sprays of infectious material. Utility gloves are not necessary.

Public health guidelines recommend that laboratory specimens for influenza testing must be manipulated using which of the following safety precautions?

69. This patient is most likely suffering from sickle cell anemia. This cell, which is sickle-shaped, is indicative of the presence of hemoglobin S. Polychromasia is also commonly observed in sickle cell anemia.

After experiencing crippling pain in her chest, Elizabeth's mother rushes her to the Emergency Room. After a complete blood count and differential are ordered, the hematology technologist views many peripheral cells similar in appearance to those found in the image below.

Which condition is most likely present?

70. Beta-thalassemia major, also known as Cooley's anemia, has inherited two genes for beta thalassemia without a normal beta-chain gene. This disease is assoicated with a marked deficiency in beta chain production and in the production of normal Hb

A. These patients exhibit increased amounts of iron due to the mutliple transfusions that keep them alive. There is also a striking increase in hemoglobin F and an elevation in hemoglobin A2.

Hematology

A 5-year-old African American child with hepato-splenomegaly and skeletal abnormalities has the following lab results:

WBC = 4,800/cu.mm

20 NRBC/100 WBC

RBC = 2.70 X 106

HGB = 6.2 g/dL

Many target cells

Marked hypochromasia, anisocytosis & poikilocytosis

Serum Iron = 200 µg/dL (elevated)

Sickle Solubility = negative

Hemoglobin F = elevated

What is the PROBABLE cause of these findings?

A. Aplastic anemia

B. Beta-thalassemia major

C. Sickle cell anemia

D. Hemoglobin C disease

71. Sally is seeing her new primary care provider for the first time. When she signs in, she is asked to sign papers for the release of medical records, including her laboratory results. According to the Health Insurance Portability and Accountability Act (HIPAA), she must authorize release of records before _______________would be permitted to receive and review her records.

72. AABB Standards do not require a DAT, autologous control, or a minor crossmatch for pretransfusion testing.

Essential components of compatibility testing include all of the following except :

73. According to OSHA, Hazard Communication 1910.1200 has the purpose of ensuring that the hazards of all chemicals produced or imported are evaluated, and that information concerning their hazards is transmitted to employers and employees.

Also known as the "Right To Know Law," which one of the following OSHA regulations first dealt with specific information related to the contents of chemicals used in the workplace?

74. This integrity of this specimen is compromised. The unit cannot be used.

What action should be taken if a large clot is noticed in a red blood cell unit while the product is being prepared for release to the patient?

75. A young man is experiencing difficult breathing after fainting. The physician orders a blood gas analysis which shows the following results:

pH = 7.25

pCO2 = 62 mmHg

pO2 = 70 mmHg

HCO3 = 23 mEq/L

Which condition is most likely afflicting this patient?

76. Granulocytes are the most granular population; they have the most side scatter of the cell populations that are listed.

Which of these white blood cell populations would have the MOST side scatter when analyzed using flow cytometry?

77. Atherosclerosis is a hardening of an artery specifically due to the build up of plaque. The risk to patients with significant atherosclerosis is that eventually a narrowing of the artery (stenosis) can cause a reduction in oxygen delivery to tissues and plaque rupture can lead to an acute coronary event.

Atherosclerosis is a hardening of an artery specifically due to which of the following?

78. Elevation in conjugated bilirubin is most likely to be found in which of the following conditions:

79. Which of the following organizations has developed standards to maintain the performance of the clinical laboratory at the highest standards for quality care?

80. The color coding of evacuated tubes provides information about all of the following except the: Question options:

81. Which of the following is most likely to interact with arterial walls, leading to deposition of cholesterol, and initiating or worsening atherosclerosis?

82. Yellow stopper tubes are used for all of the following except:

Question options:

83. Interferon gamma serves various purposes in immunologic response, including the promotion of natural killer cell activity as well as decreased viral replication by using enzymes to decrease protein replication, both viral or host, inside of the cell.

The lymphokine most important for increased natural killer cell activity and decreased viral replication in cells is:

84. This scenario's answer can be calculated by first deciding what the total quality control labor costs are as well as what the total consumable costs are. In this case, if quality control is run 3 times per day, a total of 1095 quality control runs are performed each year. The direct labor cost of $2.63 multiplied by 1095 quality control runs equals $2879.85 per year in quality control direct labor. The hospital pays $354.00 per month on quality control consumables, which equals $4248.00 per year. The total quality control costs in a year are equal to $2879.85 + $4248.00 = $7127.85. If 76,000 new chemistry tests panels are peformed each year, the total quality control cost per new chemistry test panel will be $0.09.

General Hospital is considering the addition of a new chemistry panel containing 12 tests. The laboratory is asked to calculate the total cost of quality control per new chemistry test panel. Quality control must be performed 3 times per day (every 8 hours). The labor cost per quality control test for this panel is $2.63. A month's worth of quality control reagent costs $354.00.

What is the total quality control cost per new chemistry test panel if 76,000 of these new panels are performed each year?

85. Beer's law is based on the fact that absorbance is directly proportional to the concentration of a solution. Therefore, stray light can alter the absorbance results in this type of assay.

Deviations from Beer's Law are caused by:

86. Lipids tend to form a "maltese cross" pattern when viewed in polarized light, which helps to differentiate them from other urine microscopic components.

Substances found in urinary sediment that are more easily distinguished by use of polarized microscope are:

87. Polyspecific antihuman globulin (AHG) reagent contains both anti-IgG and anti-C3d.

Polyspecific antihuman globulin (AHG) reagent used in antiglobulin testing should react with which one of the following?

88. The electrolyte panel consists of potassium, sodium, chloride, carbon dioxide. These analytes are also typically ordered within other panels as well, including the basic metabolic and complete metabolic panels.

An electrolyte panel (lytes, chem-4) consists of:

89. The DAT, or direct antiglobulin test, is used to detect antibodies coating RBC's in vivo.

The Direct Antiglobulin Test (DAT) is usually used to detect:

90. The term universal precautions refers to:

91. This is the total magnification of the high dry objective lens.

92. CORRECT TEXT

Match terms with fragments resulting from papain digestion of an IgG molecule:





A = Fab fragment OR Fc fragment

B = Fab fragment OR Fc fragment

93. Vitamin K dependent factors are those that require Vitamin K for their synthesis in the liver. Vitamin K is an important factor to gamma-glutamyl carboxylase which adds a carboxyl group to glutamic acid residues on factors II, VII, IX and X, as well as Protein S, Protein C. In adding the gamma-carboxyl group to glutamate residues on the immature clotting factors Vitamin K is itself oxidized. Deficiency of Vitamin K due to malabsorption, liver disease, etc. may contribute to bleeding disorders because clotting factor maturation depends on Vitamin K.

Which of these coagulation factors are referred to as "vitamin-K dependent?"

94. The personal protective equipment (PPE) that is used in the laboratory to protect the personnel when performing tests on patient blood samples is which of the following:

95. This type of laboratory professional is responsible for the technical aspects of managing

the operation of the laboratory and is most likely an MLS with additional education in administration:

96. Clostridium difficile is a gram-positive, anaerobic, spore-forming bacillus that produces a strong toxin. C difficile is a common cause of antibiotic-associated diarrhea and pseudomembranous colitis.

Microbiology

A recto-sigmoidoscopy revealed pseudomembranes in a patient with severe diarrhea following prolonged treatment with ampicillin.

Which of the following organisms is MOST likely to be isolated?

97. Angina

98. Hives and rash usually indicate an allergic reaction. Hematuria is due to a variety of causes. Fever and chills usually indicate a febrile reaction. Positive DAT due to conditions other than sensitization to red cell alloantigens is not uncommon. Therefore a positive DAT in the posttransfusion specimen with a negative DAT in the pretransfusion specimen is more likely to indicate alloimmunization.

The most definite indication that a patient has been sensitized to a specific red cell antigen is:

99. A cardiac risk profile is performed in:

100. The correct answer which best fits the characteristics in this question is Mycobacterium tuberculosis.

What is the MOST likely identity of an acid-fast bacilli that showed buff colored, dry, heaped colonies; niacin, nitrate, and urease positive; and took 23 days at 35ºC to grow?

101. Twelve weeks after onset of the disease, patients with uncomplicated acute hepatitis B usually will demonstrate which of the following in their serum?

102. The production of long, tapered phialides is one of the key identifying features of Trichoderma species. In contrast, Penicillium species, produce phialides with blunt ends.





The phialides of Beauveria species are geniculate, forming a zig-zag pattern.

The arrows in the image on the right point to single, long, tapered phialides that extend laterally from either side of the hyphae. This is an identifying feature of which of the fungi listed below?

103. Assuming an alpha hemolytic reaction (not well seen in the image), viridans streptococcus and S. pneumoniae are the two possible responses. However, these colonies are far too mucoid for viridans streptococci; therefore, S. pneumoniae is the most likely choice. Also, the colonies are much too large and the hemolytic reaction is wrong for S. pyogenes or S. agalactiae.

A patient was admitted to the hospital recently with an obvious infection. A sputum specimen was submitted and the microbiologist inoculated it to sheep blood agar.

Based on the colony morphology and the alpha hemolysis seen in the image to the right, the most likely identification is:

104. The approximate volume of CSF in an adult is 90-150 mL.

What is the approximate volume of spinal fluid in an adult?

105. Valine substitutes for glutamic acid in the Beta 6 position to produce HbS.

To produce hemoglobin S, glutamic acid that is normally present in the sixth position on the beta globin chain is substituted with which of the following?

106. hs-CRP is a more sensitive version of the C-reactive protein (CRP) test, a test that has been used for many years to assess inflammation in settings such as lupus, transplantation, infection, etc.

Which of the following cardiovascular risk markers is a more sensitive version of a test that is used to assess inflammation?

107. The purpose of protective isolation is to protect:

108. Enterococcus spp. are bile esculin positive and grow in 6.5% NaCl. If they grow on the 6 µg/mL vancomycin screen agar as this isolate does, it is vancomycin resistant. If there is no growth on the 6 µg/mL vancomycin screen agar, the isolate is susceptible to vancomycin. Streptococcus Group D, not Enterococcus will not grow in the 6.5% NaCl and should not be tested for vancomycin resistance. Staphylococcus epidermidis is catalase positive.





The images below represent a gram-positive, catalase-negative, non-motile coccus inoculated to bile esculin agar, 6.5% NaCl broth and to 6 µg/mL of vancomycin in Mueller Hinton agar. It should be reported as:

109. The most likely causes of delayed hemolytic reactions are Kidd system antibodies. Both jka and jkb are often responsible for delayed hemolytic transfusion reactions.

Blood Bank

Delayed hemolytic transfusion reactions are usually caused by antibodies directed against what blood group system?

110. Conversion of only the slant to a pink color in a Christensen's urea agar slant is produced by bacterial species that have weak urease activity. The reaction in the slant to the right is often produced by Klebsiella species, as an example. Strong urease activity is indicated by conversion of the slant and the butt of the tube to a pink color, as seen in the tube to the left. The slant only reaction in the right tube may be seen early on if only the slant had been inoculated; however, with a strong urease producer, both the slant and the butt would turn. Therefore, the reaction is dependent on the strength of urease activity. If the media had outdated for a prolonged period, either there would be no reaction or the appearance of only a faint pink tinge, either in the slant, the butt or both, again depending on the strength of urease production by the unknown organism.

The urease reaction seen in the Christensen's urea agar slant on the far right indicates:

111. The ApoB/ApoA1 ratio has a positive risk marker (ApoB-100) and a negative risk marker (ApoA1). Risk diminishes as ApoA1 goes up (a negative marker) and risk increases in proportion to ApoB concentrations (a positive risk marker). This 'double-edged sword' provides good risk prediction. The other risk markers in question do not have this dual-advantage.

Which risk marker has both positive and negative cardiovascular risk integrated into its measurement?

112. A phlebotomist draws an outpatient without wearing gloves. The outpatient displays a badge and cites the laboratory for not following the law.

The outpatient is an employee of the:

113. AHG must be added to the cells immediately following washing. Antibodies may elute from the cells if the cells are allowed to sit in saline without the addition of AHG.

Which one of the following may cause a FALSE-NEGATIVE result with antiglobulin techniques?

114. Hepatitis B surface antigen, or HBs, is a protein that is present on the surface of the virus. The protein will be present via laboratory testing in the blood with acute and chronic HBV infections

Immunology

What sero-marker is the first marker to become positive in Hepatitis B and is associated with the infective stage?

115. Normal pH of semen must be a value equal to or greater than which of the following?

116. The primary mechanism responsible for glomerular filtration is:

117. Ferritin and hemosiderin are considered storage forms of iron.

Which substance(s) is/are considered iron storage compounds?

118. Amniotic fluid bilirubin is increased in association with the severity of hemolytic diseases of the newborn. As red blood cells lyse during these conditions, bilirubin builds up as a byproduct of the red cell destruction. The more red blood cells that are being destroyed in the baby, the more increased the bilirubin level will become.

Which one of the following tests BEST correlates with the severity of hemolytic disease of the newborn (HDN).

119. RAST tests, or Radioallergosorbent tests, are used to screen for an allergy to a specific substance or substances if a person presents with allergy-like symptoms.

The assay which is most helpful in identifying specific allergens is:

120. Either immunofixation or immunoelectrophoresis can be used to confirm Bence-Jones proteinuria.

Which of the following methods would be used to confirm the presence of Bence-Jones protein in the urine:

121. No HLA matching is performed for corneal tissue transplants as the cornea occupies a privileged site not usually seen by the immune system. This term has been coined "immune privileged".

Corneal tissue may be transplanted successfully from one patient to another because:

122. Convert the following temperature from Celsius to Fahrenheit -4 degrees C

123. In which disorder do neonates demonstrate the presence of Bart's hemoglobin that changes to beta chain tetramers in adults?

124. Waived tests are those considered to have an insignificant risk of erroneous results.

Which of the following is NOT an example of a waived test?

125. Streptococcus pyogenes is the correct answer. Streptococcus pneumoniae is alpha-hemolytic which demonstrate a green area of partial hemolysis around the colonies. Staphylococcus aureus will produce complete hemolysis but is catalase positive.

Streptococcus agalactiae is beta-hemolytic but only produces a partial clearing of the red blood cells in sheep blood agar.

Complete hemolysis of sheep blood agar as demonstrated by the image below would be seen in which of the following catalase-negative isolates?

126. The part of the microscope that holds the objective lenses is called the _______________.

127. Anti-A, anti-P, anti-Leb, and anti-M all react best at 4o C as they are predominantly IgM antibodies. Other antibody group choices above include IgG antibodies such as anti-K, anti-s, anti-S, and anti-Fya, anti-Lub, etc. which react best at 37o C.

Which of the following groups of antibodies generally reacts most strongly at 4o C:

128. A laboratory scientist is working the night shift at a local hospital when the power goes out.

What is the course of action to continue to provide laboratory results?

129. Microcontainer collection order of draw differs from regular peripheral blood collection order of draw. When performing a capillary draw, the lavender top container is obtained first. This decreases the possibility of clots in the container which would invalidate the results of the complete blood count test.

After the lavender is drawn, other containers with anticoagulants would be collected, and containers without anticoagulants would be collected last.

A phlebotomist must perform a skin puncture to obtain capillary specimens for a complete blood count (CBC), a plasma-based chemistry test, and a serum-based immunology test. The microcollection containers that will be used are lavender top containing EDTA anticoagulant, green top containing heparin anticoagulant, and gold top containing no anticoagulant.

Which microcollection container should be collected first?

130. The correct response is option B: The Hepatitis B "e" Antigen (HBeAg). This antigen indicates the virus is actively replicating and therefore the patient is very infectious. The hepatitis B "e" antigen is present when the virus is actively replicating. In cases of unintentional needlesticks, infectivity is of highest concern. The risk for infection is greatest during phases of increased HBeAg serology. The Hepatitis B surface antigen is the first detectable marker, but if the patient is known to have Hepatitis B already, it would be relatively unhelpful to confirm the condition with another HBsAG test. The core antigen is not detectable because it is covered by the nuclear envelope. Antibody response patterns would not be very helpful either as the patient has already been diagnosed with acute Hepatitis

B. IgG antibodies would indicate recovery, which is not the case for this patient and IgM antibodies indicating a recent or acute infection would only confirm what is already known. Recall, in cases of unintentional needlesticks, infectivity is of highest concern.

A phlebotomist at a local hospital recently had an accidental needle stick while drawing blood from a patient being treated for acute hepatitis B.

Which serological marker from the patient would be of most value to the physician evaluating the phlebotomist's possible infection status?

131. Intravascular hemolysis is typically associated with increased levels of serum (plasma) LDH and bilirubin, and an increased number of reticulocytes. Serum LDH is found in higher levels during intravascular hemolysis due to fact that high levels of LDH are normally found within the red cells, but is now being spilled into the bloodstream via red cell lysis. Bilirubin is a breakdown product of hemoglobin, which has also been spilled into the bloodstream from broken red blood cells via hemolysis. Reticulocytosis is a reflection of the release of an increased number of immature red blood cells from the marrow to account for the red blood cells that are lost through hemolysis. This is a normal response. Failure to show an increased reticulocyte count with hemolytic episodes or hemorrhage would indicate an ineffective erythropoiesis (possible bone marrow function problem).

Which of these blood levels will increase during intravascular hemolysis?

132. Cholesterol levels do not fluctuate as triglycerides, fatty acids, lipoproteins, and chylomicrons do after an individual eats a meal. This is the reason that patients are told to fast; the laboratory needs a fasting sample to determine a lipid profile or panel which includes the latter four components.

Which of the following lipid tests is LEAST affected by the fasting status of the patient?

133. Free T4 is affected the least by changes in plasma proteins during pregnancy.

Which of the following thyroid function assays is affected least by pregnancy:

134. Heinz bodies occur as the result of denaturation and precipitation of hemoglobin, and are often attached to the red cell membrane. They require staining with crystal violet or methyl violet to be visible. They may be seen in thalassemia, with unstable hemoglobins, or during a hemolytic episode in G6PD deficiency.

Hematology

The intracellular precipitates seen in the RBCs in this illustration is termed:

135. Hemoglobin F has a high affinity for oxygen. When Hb F is elevated, cells containing Hb S are more oxygenated and do not sickle as readily as they would if Hb F were not present or present in small quantities.

Which hemoglobin, when elevated, acts as a protection against sickling in patients with HbS?

136. Isolation and detection of Gardnerella vaginalis from vaginal secretions is improved by which of the following?

137. Immunology

The immunoglobulin molecule is made up of both heavy and light chains - the light chains can be comprised of which of the following:

138. Allergen-specific IgE, synthesized in response to allergens, becomes fixed to receptors on cellular membranes, especially those of basophils. If these receptor-bound IgE molecules are aggregated on re-exposure to specific allergen, both mast cells and basophils produce mediators that result in the allergic response. IgE-antigen interaction at the cell surface causes degranulation of cells and release of substances including: histamine, SRS-A, platelet activator, a kallikrein, and an eosinophil chemotactic factor. Basophils are the principal cells that bind IgE antibody while their number of receptor sites is proportional to serum IgE levels. Eosinophils are drawn to the site by the basophil chemotaxis mechanism, but are not the main cell which binds the IgE antibody.

Immunology

The mediator cells that bind MOST to IgE antibodies are:

139. Although cysteine-blood agar was traditionally used, F. tularensis will also grow on commercially available Thayer-Martin and chocolate agar which have been enriched with supplemental nutrients.

Which of the following media would you use to isolate Francisella tularensis:

140. A patient with tuberculosis would be placed in:

141. There are many causes of CSF lymphocytosis. Lymphocytosis is seen in viral, fungal, and

tuberculous infections, although a predominance of neutrophils may be present in the early stages of these infections. Lumbar puncture to obtain CSF samples is often contraindicated in those with a suspected brain abscess.

CSF lymphocytosis is associated with all of the following except:

142. One of the following may cause a laboratory acquired infection (LAI):

143. During primary hypothyroidism, where a defect in the thryoid gland is producing low levels of T3 and T4, the TSH level is increased. TSH is released in elevated quantities in an attempt to stimulate the thryoid to produce more T3 and T4 as part of a feedback mechanism.

Serum TSH levels five-times the upper limit of normal in the presence of a low T4 and low T3 uptake could mean which of the following:

144. A test with high specificity accurately detects the absence of disease. The more specific a test is, the fewer false-positive results will occur. A test with high sensitivity accurately identifies the presence of disease. The more sensitive a test, the fewer false-negative results it produces. In the case stated in this question, the immunoassay has high specificity, so it has few false-positives and will accurately detect those individuals who do not have the disease or condition that is being tested for. However, the test has low sensitivity, so it may not identify all individuals who actually have the disease; it may produce many false-negative results.

The accuracy of an immunoassay is its ability to discriminate between results that are true positives and results that are true negatives. Two parameters of test accuracy are specificity and sensitivity.

Which of these statements apply to an immunoassay with high

specificity, but low sensitivity?

145. The role of the laboratory supervisor or manager is to

146. The renal threshold is the maximum amount of a substance that the kidney can prevent from entering into the urine.

UA & body fluids

The renal threshold is best described as:

147. If Kappa or Lambda is predominant and CD5 is co-expressed with CD19 (CD19/CD5 dual positive lymphocyte population), and CD23 is expressed, chronic lymphocytic leukemia is a probable diagnosis. CD19 is normally found on normal B cell populations and CD5 is normally found on mature T cell populations. However, CD5 is present on B cells in B-chronic lymphocytic leukemia or Mantle Cell Lymphoma, both abnormal B cell malignant processes.

CD23 expression is not consistent with Mantel cells as shown on the decision tree on the right.

A monoclonal B-cell population (Kappa or Lambda predominant) with expression of CD19, CD20, CD23, and co-expression of CD5 is consistent with which of the following?