Clinical Laboratory Science Practice Exam

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• Plasma cells evolve from which cell line?
• After febrile reactions to red cell transfusions, which component is best for subsequent transfusions?
• In thin-layer chromatography used for drug testing, what is the essential purpose of the solvent?
• Abnormal PFA results and giant platelets best describe which syndrome?
• A clean catch urine from a female with suspected UTI shows Gram-positive cocci that are catalase positive, coagulase negative, and staph latex negative; novobiocin panel shows growth. Which organism is most likely?
• Which cyst has a nucleus with a prominent karyosome, a clear halo, no achromatic granules, and no peripheral chromatin?
• A fungal specimen from bone marrow of a patient with pulmonary infection shows tuberculate macroconidia at 30C and yeast-like cells at 36C. Identify the most likely dimorphic fungus.
• A 4-year-old boy has a prolonged aPTT of 53 seconds. Mixing with normal plasma at a 1:1 ratio yields an aPTT of 50 seconds. Which of the following is most likely?
• Dosing warfarin should be based on genotyping for which genes?
• An elevated white blood cell count with neutrophilia, a left shift, toxic granulation, vacuoles, Dohle bodies, and an increased LAP is most consistent with which scenario?
• RT-PCR involves all of the following except which step?
• Calculate the creatinine clearance of a 24-hour urine sample using the following data: urine creatinine 500 mg/dL, plasma creatinine 8 mg/dL, urine volume 1.5 L.
• A 2-hour post-load glucose value of 238 mg/dL after an OGTT indicates which diagnosis?
• Which disorder would be associated with a right shift in the RBC histogram?
• If an employee suspects the employer is violating safety standards, which agency should be notified?
• The normal myeloid-to-erythroid (M:E) ratio in an adult is approximately?
• Which organism shows trophozoites that ingest red blood cells?
• Why should potassium levels be monitored before and during IV insulin therapy?
• Which organism is classically described as causing gas gangrene with double-zone beta-hemolysis under anaerobic conditions?
• Oligoclonal IgG bands in CSF are most characteristic of which condition?
• Which of the following is an accrediting agency?
• Which cytogenetic abnormality is diagnostic of acute promyelocytic leukemia (APL)?
• Which serologic pattern is most characteristic of Sjogren's syndrome?
• A patient has a T helper:T cytotoxic ratio of 1:2. Which disease state might you expect?
• To determine if alpha-hemolytic cocci from sputum are Streptococcus pneumoniae, which test should be performed?
• In drug testing using thin-layer chromatography, why is a volatile organic solvent mixed with urine specimens?
• An aPTT performed on a patient on high-dose warfarin therapy would be expected to be:
• Which organism is known to produce a distinctive red pigment in some strains?
• An L/S ratio of 2.7 indicates:
• Which organism is typically identified on a silver stain in respiratory samples from AIDS patients?
• An arterial blood gas sample arrives 45 minutes after collection with an air bubble in the syringe. What should the technologist do?
• APL involves a fusion gene created by t(15;17). Which fusion gene is produced by this translocation?
• In flow cytometry panels, using CD3/CD4 and CD3/CD8 mixtures ensures quality by counting which cells as positive?
• Thick-walled yeast cells bearing single buds attached by a broad base are observed in an aspirated clinical specimen. The organism is most likely:
• Which parasite is a protozoan that can be transmitted by tick bites and blood transfusions?
• An oral glucose tolerance test yields fasting serum glucose of 128 mg/dL and a 2-hour post-load glucose of 238 mg/dL. This result most strongly correlates with which diagnosis?
• A blood ammonia level ordered for a patient with Reye's syndrome on a clotted sample returns normal. What is the most likely explanation?
• Which organism can cause fatal meningitis and is commonly associated with warm freshwater exposure?
• A patient with positive ANA has anti-Sm negative, anti-SSA positive, anti-SSB positive, anti-Scl-70 negative, anti-RANA negative. What is the most likely diagnosis?
• Which finding is associated with a false increase in hemoglobin as well as the MCV and RBC count?
• Which temperature is optimal for the growth of Campylobacter jejuni?
• An MCV of 74 fL is best described as which red blood cell category?
• Differentiating Cryptosporidium parvum from Cyclospora cayetanensis in stool samples is primarily based on which feature?
• A 22-year-old female presents in the ER with a spider bite. Lab results show schistocytes on a blood smear, platelets 50, PT 20, aPTT 60, and a positive d-dimer. The most likely diagnosis is:
• A specimen tested for varicella antibodies yields titers of 320, then 640 two weeks later, then 320 four weeks after the first test. What is the disease status?
• ANA testing shows a speckled pattern with a titer of 640. What is the recommended next test?
• Given a WBC count of 5,500/µL, lymphocytes at 20%, and CD4 cells at 25% of lymphocytes, what is the absolute CD4 count?
• X-linked recessive traits are more common in
• Which specimen type is noted as the specimen of choice for suspected epiglottitis in this context?
• Which test is commonly used to identify Pseudomonas aeruginosa in clinical specimens?
• Which virus is the etiologic agent of acute infectious infantile diarrhea?
• An elevated RDW on a CBC indicates which finding about red blood cells?
• Which statement about TRH stimulation testing helps differentiate hypothalamic from pituitary dysfunction?
• Which condition is most likely to yield a rightward shift in the RBC histogram?
• Cord bloods are washed prior to ABO and Rh grouping for what purpose?
• If an individual shows both normal and mutant bands, the genotype is described as
• Calculate the LDL cholesterol given total cholesterol 250 mg/dL, HDL 40 mg/dL, and triglycerides 210 mg/dL (use Friedewald equation).
• Which test is commonly used after a positive ANA to identify specific autoantibody groups?
• The most common light source for spectrophotometry in the visible range is which of the following?
• Which of the following laboratory features is consistent with disseminated intravascular coagulation with secondary fibrinolysis?
• In performing a manual WBC count, 0.02 mL of blood was diluted with 1.98 mL of ammonium oxalate and an average of 50 cells was counted with a Neubauer hemocytometer. What is the patient’s white cell count per microliter?
• An antibody screen gave no reactions at immediate spin or 37C, but showed a 2+ reaction when AHG was added. The most likely antibody causing these results would be
• The reagent strip reaction used to test for the presence of glucose is based on:
• When staining a serum protein electrophoresis plate, if no bands are observed in controls and patient samples, what is a likely cause?
• In HIV infection, a CD4 to CD8 ratio that is decreased (e.g., 1:2) is most commonly associated with which condition?
• In obstructive jaundice, which bilirubin fraction is predominantly elevated?
• The migration rate of a macromolecule through a gel matrix during electrophoresis depends on which factors?
• Which organism is transmitted to humans by ticks and blood transfusions?
• A sample from bluish purulent head lesions yields a Gram-negative, motile, non-spore-forming oxidase-positive rod. Which organism is most likely?
• Which test is the most accurate indicator of the presence of inflammation?
• Which trophozoite is suspected if ingested red cells are seen on a saline wet mount?
• Which sputum sample quality indicates an appropriate collection?
• The protein fraction that migrates most rapidly toward the anode is which of the following?
• Which infection is associated with Negri bodies in brain tissue?
• TRH stimulation test results show TSH rising to 6.0 at 30 minutes and 15.0 at 60 minutes. These results indicate which condition?
• What change occurs in a urine specimen if it is left at room temperature for longer than 1-2 hours?
• Reticulocyte count in pernicious anemia is typically which of the following?
• The concept that lab personnel should treat all blood and body fluids as capable of transmitting infectious diseases is known as?
• What type of instrumentation is based on measuring energy emission that occurs when compounds absorb electromagnetic radiation, become excited and return to lower energy levels?
• Which parasite egg may not be detected in zinc flotation procedures?
• A photochromogenic mycobacterium isolated at 30°C is most likely which species?
• What percent of the total white blood cell count is represented by CD4 cells in this data set?
• Using the given data, what is the lymphocyte count per microliter?
• Which parasite is a lung-dwelling fluke that can be misdiagnosed as tuberculosis due to pulmonary symptoms?
• Red blood cells which are to be tested with AHG are washed to
• Electrophoresis of CSF showing multiple homogeneous IgG bands by immunofixation is most consistent with which disease?
• A silver methenamine stained slide of a bronchial washing from an AIDS patient is examined. Which organism is most likely identified?
• The coding sequences of a gene are known as
• An automated CBC shows Hgb 11.2 g/dL, Hct 2.1%, RBC 2.1 x10^12/L, MCV 128 fL, MCH 53.3 pg, MCHC 41.5 g/dL, RDW 19%, and the sample was flagged with no clots. What is the next appropriate step?
• Loeffler's medium is used as a primary isolation medium for which organism?
• A260/A280 ratio around 0.23 for a DNA sample most closely indicates contamination with
• In obstructive jaundice, which fecal marker is decreased?
• During electrophoresis, crescent-shaped bands develop. The next course of action is to repeat the electrophoresis and which of the following?
• Waterhouse-Friderichsen syndrome is bacteremic and associated with which organism?
• Which parameter is most likely affected by lipemia?
• Which enzyme is decreased in organophosphate insecticide poisoning?
• Based on the following results, select the best conclusion: Mother MM R0R0; Alleged father MM rr; Child MN R0r; the alleged father is
• Which enzyme pattern is most characteristic of muscular dystrophy as opposed to liver disease?
• For an RNA sample, the 1:200 dilution yields an A260 of 0.210. What is the RNA concentration in μg/mL for the diluted sample?
• Autoclave sterilization of lab media requires which parameters?
• Elevated serum levels of creatine kinase, aldolase, and aspartate aminotransferase with normal alanine aminotransferase most likely indicate what condition?
• Enterobius vermicularis infection is usually diagnosed by finding eggs from
• What is the major iron storage compound in humans?
• To test for antibodies to specific allergens, which procedure would be performed?
• Which statement best distinguishes nephrotic syndrome from nephritic syndrome on urinalysis?
• Which condition is most consistent with macrocytic anemia with low B12 and positive anti-intrinsic factor antibodies?
• Which factor most commonly leads to a falsely normal ammonia result in suspected Reye's syndrome?
• What is the characteristic morphological form of blastomycosis observed in tissue?
• Elevated conjugated bilirubin in serum and urine, decreased urine urobilinogen, and decreased fecal urobilin is characteristic of which type of jaundice?
• A gram-negative rod isolated from urine of a female with recurrent UTI is oxidase negative and urease positive, with A/A on TSI and hydrogen sulfide production; on LIA it shows red/black. Which organism is most likely?
• The L/S ratio is used to assess what aspect of fetal physiology?
• A urinalysis on a 3-year-old reveals a positive copper reduction test and a negative glucose oxidase test. How would these results be interpreted?
• Specimens for viral culture should be transported in which medium?
• Which testing step ensures that anti-D reagent is functioning properly and rules out false positives due to other factors?
• Chemical and microscopic analysis of a urine specimen shows Protein 4+, RBC 0-2/hpf, WBC 0-5/hpf, few hyaline casts, moderate fatty, waxy, and granular casts, and many oval fat bodies. The diagnosis is:
• Which lipid parameter is most strongly associated with increased cardiovascular risk?
• An elevated urine urobilinogen with a negative urine bilirubin result may indicate which condition?
• In bichromatic analysis used in automation, blanking is performed to blank for background interference.
• Which may be a source of error in electromechanical clot detection methods?
• The trophozoite of which organism is characterized by "falling leaf motility" two nuclei, an axostyle, 4 pair of flagella and a sucker on the underside of the organism?
• Crust from a cauliflower-like lesion on the hand with brown spherical bodies 6-12 mm in diameter, and after 3 weeks a slow-growing black mold on Sabouraud dextrose agar with Sporulation similar to Cladosporium, Phialophora and Fonsecaea. The probable identification is:
• One cycle of PCR includes which steps?
• What is the concentration of RNA in the diluted sample with A260 0.210 at 1:200?
• Which organism is primarily isolated on Loeffler's medium?
• Which phase of testing is most likely to reveal clinically significant antibodies that do not react at immediate spin or 37 C?
• AB plasma is considered the universal plasma donor because it lacks which antibodies?
• Which organism is a dimorphic fungus that forms yeast at body temperature and mold in the environment, commonly causing granulomatous disease?
• Which statement best describes fetal-maternal hemorrhage?
• Which of the following lipid profiles indicates the greatest risk for coronary disease?
• Which organism is associated with chromoblastomycosis and was identified as pedrosoi in this case?
• From a DNA sample with A260 0.430 at 1:100, the undiluted concentration is
• A 7-year-old child with prolonged PT and normal aPTT is being evaluated before ear tube surgery. Which condition is most likely?
• Which test detects antibodies to specific allergens using a radioimmunoassay technique?
• What is the best test for detecting cystic fibrosis?
• What is the proper initial action when a formalin spill occurs in the laboratory?
• Restriction endonucleases recognize specific
• What type of urine specimen is considered the ideal screening specimen because it is the most concentrated?
• In a pooled platelet product, if pooling occurred at 2:00 pm and the product becomes outdated by 6:00 pm, what is its allowable storage duration in this scenario?
• A patient suspected of having syphilis had RPR reactive, FTA-ABS nonreactive, and VDRL (CSF) nonreactive. What is the most likely interpretation?
• To prove a yeast is dimorphic, which test is performed?
• Immunofluorescence testing for EBV shows anti-VCA, anti-EA, and anti-EBNA antibodies. How would this be interpreted?
• What is the best method for screening cerebrospinal fluid for syphilis?
• Which statement correctly describes the relationship among WBC, lymph percent, and CD4 percent?
• Which organism is an amoeba that can form liver abscesses in humans?
• Which combination of hepatitis B serologic markers indicates a highly infectious stage?
• In a patient with signs of heart failure, which test is most appropriate to order to assess for cardiac involvement?
• A yeast-like organism isolated from a sputum specimen on cornmeal agar produces mycelia with thick-walled terminal chlamydoconidia. The organism is most likely which species?
• Which genus includes species that are Gram-negative, motile rods and may produce a red pigment, implicated in septicemia, pneumonia, and UTIs?
• Decreased synthesis of globin chains is most characteristic of which disorder?
• Four units of platelets were pooled at 2:00 pm; at 7:00 pm the ward asked if they could still be used, but they were outdated at 6:00 pm. What is the correct status of the pool?
• Which assay is the most sensitive and specific for all stages of syphilis?
• Which of the following would be considered personal protective equipment?
• After measles exposure, if the initial titer is 1:20, what is the recommended next step?
• A patient with travel history and suspected TB has a sputum sample that is blood-tinged with orange/brown flecks. Which parasite may be suspected?
• Which statement best describes the laboratory pattern associated with vitamin K deficiency?
• What is the treatment of choice for methicillin-resistant Staphylococcus aureus (MRSA) infections?
• How many units of platelet concentrates are typically required to raise the platelet count by 150,000/mm3 in an average-sized adult?
• Which pattern of TSH response to TRH stimulation would most strongly suggest hypothalamic (tertiary) dysfunction?
• What type of fire extinguisher would be best to use on computer equipment?
• The biuret method for determining serum total protein is dependent upon which structural feature of proteins?
• In CSF from viral meningitis, which cell type is typically elevated?
• Differential diagnosis of Cryptosporidium parvum and Cyclospora cayetanensis is based on which feature?
• Multiple myeloma most commonly involves which class of immunoglobulin?
• A DNA sample shows OD260 0.041 at a 1:50 dilution. The diluted sample concentration is
• Which of the following can cause a fatal meningoencephalitis?
• Which test result most strongly supports a diagnosis of pernicious anemia?
• A DNA preparation has A260 = 0.260 and A280 = 0.230. Based on the ratio, the sample is
• For which of the following blood groups is it NOT necessary to run an Rh control if you are using a monoclonal/polyclonal blend anti-D?
• Over a two week period, the reactions of your QC antibody show a gradual decrease from 2+ to a very weak positive with your antibody detection cells (screening cells). These results most likely indicate
• Which of the following would cause an individual to be rejected as a blood donor?
• The human genome consists of approximately how many bases?
• Which manual laboratory test would be most affected by using an EDTA sample that contains only about 1 mL of whole blood?
• Anti-Jka antibodies are directed against which red blood cell antigen?
• The failure of granulocytes to mature beyond the banded or two-lobed stage is characteristic of which condition?
• A DNA sample yielded an OD260 of 0.041 at a 1:50 dilution from a 0.4 mL sample. What is the total amount of DNA in the 0.4 mL sample?
• Which organism is classically associated with rice-water stools?
• Which is a cause of acute infectious infantile diarrhea?
• To monitor long-term glycemic control in a patient with diabetes, which test is most appropriate?
• Which laboratory result is typically not affected by sample hemolysis?
• In a prolonged aPTT that does not correct with mixing with normal plasma, which is most likely?
• Plasma cell (multiple) myeloma may be suspected if which of the following is seen on a peripheral smear?
• A clinical lab's first response to a formalin spill in the lab should be to?
• Which stain is used to visualize iron-containing inclusions in red blood cells such as siderocytes and Pappenheimer bodies?
• Which organism causes visceral larval migrans?
• An organism recovered from a diarrheal stool yields a K/A result with no gas or H2S on TSI; lysine negative; oxidase negative; urease negative; citrate negative. Most likely organism?
• The causal agent of chancroid is which organism?
• A bone marrow differential shows 20% blasts with flow cytometry showing CD10+, CD19+, CD22+ and CD13/CD33-. Which disease is most compatible?
• The transfusion component of choice for a bleeding patient with prolonged bleeding time, increased aPTT, decreased factor VIII antigen, and impaired ristocetin aggregation would be which component?
• A sample from a 20-year-old donor shows anti-A 3+, anti-B 0, A1 cell 1+, B cell 3+, O cell 0. The most likely cause of this discrepancy is
• Which organism is a scotochromogenic mycobacterium that hydrolyzes Tween 80 in 7 days?
• Which combination of surface markers is most characteristic of precursor B-cell acute lymphoblastic leukemia?
• Which organism is associated with gas gangrene, known for stormy fermentation and double-zone beta-hemolysis on anaerobic culture?
• What is the most likely cause of subacute bacterial endocarditis?
• For a DNA sample, the 1:100 dilution yields an A260 of 0.430. What is the DNA concentration in μg/mL for the original sample?
• A varicella-zoster antibody pattern with rising and falling titers over weeks is most consistent with which status?
• In diabetic ketoacidosis, which arterial blood gas pattern best describes the acid-base status?
• In vaginal infections presenting with a fishy odor after KOH, the most likely etiologic organism is which of the following?
• Which test is most useful for differentiating Citrobacter from Salmonella?
• If humans ingest the egg of Taenia solium, they may develop
• What is the concentration of DNA in the diluted sample with A260 0.430 at 1:100?
• A peripheral blood smear shows siderocytes on Prussian blue staining. On a Wright stained smear, what would you expect to see?
• Which species is a photochromogenic mycobacterium that grows at approximately 30°C?
• Western blotting is a method used to detect which biomolecule?
• Which diagnostic clue most strongly supports Staphylococcus saprophyticus as the cause of a female outpatient urinary tract infection?
• CSF analysis shows increased protein, normal glucose, normal lactate, and increased lymphocytes. This pattern most strongly indicates which condition?
• A microfilaria observed in a skin nodule from a patient in Central America is most likely which organism?
• Which agency is responsible for enforcing workplace safety standards in the United States?
• Which disease state is most suggested by HBsAg positive, HBeAg positive, anti-HBc positive, anti-HBe negative, and anti-HBsAg negative?
• The following reactions were obtained on testing maternal serum and infant cord cells: Maternal sample O-; D test: mf; D control: -; negative antibody screen; Infant cord cells A+; DAT:-. The most likely explanation is
• Cryoprecipitate is particularly rich in which coagulation factors?
• Universal precautions is the concept that requires treating all blood and body fluids as potentially infectious.
• In endocarditis due to streptococci group D, which antibiotic combination is described as synergistic?
• The organism whose trophozoite shows falling leaf motility is:
• A patient shows a negative dithionite solubility test and electrophoresis with bands in the A and S regions on cellulose acetate at pH 8.6; on citrate agar there is only a band in the A region. Which hemoglobin variant is compatible with these results?
• A 32-year-old woman has Hgb 9 g/dL, MCV 74 fL, MCH 27 pg, MCHC 30 g/dL, RDW 19%, ferritin 4 ng/mL, iron 29 μg/dL, TIBC 590 μg/dL, and percent saturation 5%. These results are most consistent with which type of anemia?
• Clinical diagnosis of rabies in infected animals is dependent upon observation of which brain tissue inclusion?
• Based on the following electrolyte values, which indicates a potential problem with the sodium measurement? A Na 149, Cl 102, HCO3 26; B Na 153, Cl 105, HCO3 28; C Na 150, Cl 103, HCO3 25; D Na 151, Cl 104, HCO3 27
• In suspected epiglottitis, from which specimen is the diagnostic sample most appropriately collected?
• Which item is an example of personal protective equipment?
• The amoeba which can cause liver or lung abscesses is
• After exposure to measles, a patient tests with a titer of 1:20. This result indicates which of the following actions?
• Which urinalysis finding is most characteristic of nephrotic syndrome aside from proteinuria?
• A group A patient needs blood and FFP. The hospital is out of A blood and A FFP. Which would be your first choice to transfuse to this patient?
• An individual immunized for rubella has what type of immunity?
• In iron deficiency anemia, ferritin level is typically?
• Rouleaux formation on a peripheral smear is most strongly associated with which condition?
• Which statement best describes what crescent-shaped bands indicate in electrophoresis when considering sample loading?
• The infective stage for Strongyloides stercoralis is the
• A vaginal discharge with fishy odor after 10% KOH and a wet mount showing epithelial cells and gram-variable rods most likely indicates infection with which organism?
• A blood smear showed crescent shaped gametocytes in several red cells. What is the most probable identity?
• Which organization accredits many clinical laboratories and hospitals?
• A 24 year old A negative female was transfused with approximately 65 CC of an A positive RBC unit. How many vials of RhIG should this woman receive?
• Which organism is associated with congenital infection risk through cat litter exposure?
• Pregnant women are advised to avoid cleaning litter boxes to prevent congenital infection with which organism?
• Which clinical specimen is most appropriate for detecting Onchocerca volvulus microfilariae?
• Which panels are used in flow cytometry to identify T cell subsets by co-expression of markers?
• In bichromatic analysis, blanking is used to account for background interference by measurement at which reference condition?
• Which organism is known to produce chlamydospores on cornmeal agar?