AMT Medical Laboratory Technician practice test

A serum specimen is left at room temperature for several hours before centrifugation and separation from the clot. Compared with a properly handled specimen, which analyte change is most expected because of continued cellular metabolism and leakage?

A throat culture grows beta-hemolytic colonies on sheep blood agar. The isolate is catalase negative and shows a clear zone of inhibition around a bacitracin disk. Which organism is most consistent with these findings?

A patient with a suspected autoimmune disorder has a positive antinuclear antibody screen. The laboratory performs the test using indirect immunofluorescence on HEp-2 cells. In this method, what does the fluorescent-labeled reagent bind to?

A urine specimen has a reagent strip that is positive for blood, but microscopic examination shows no red blood cells. Which of the following best explains this discrepancy?

During ABO grouping, a patient red cell suspension shows no agglutination with anti-A or anti-B, and the patient serum agglutinates both A1 cells and B cells. Which ABO blood group does this forward and reverse typing indicate?

A peripheral smear from a patient with chronic iron deficiency anemia is examined. Which combination of red cell indices and morphology is most characteristic of this condition?

A laboratory measures blood gas results on an arterial sample. The pH is low, the pCO2 is elevated, and the bicarbonate is near the upper end of normal. Which acid-base disturbance does this pattern represent?

A urine culture from a patient with a suspected urinary tract infection grows a lactose-fermenting, oxidase-negative, gram-negative rod that is indole positive and produces a green metallic sheen on eosin methylene blue agar. Which organism is most likely?

A patient was vaccinated against hepatitis B and is later tested. Which single serologic marker, if positive in isolation, best indicates immunity from vaccination rather than past natural infection?

A first morning urine specimen examined microscopically shows numerous casts with embedded red blood cells within a protein matrix. The presence of red blood cell casts most strongly suggests bleeding originating at which site?

A type and screen is ordered for a patient before surgery. The antibody screen is negative, but the laboratory still performs an immediate spin crossmatch before issuing red cells. What is the primary purpose of the immediate spin crossmatch in this situation?

During a manual platelet count, the technician notices platelet clumping on the accompanying peripheral smear, and the automated analyzer reports a low platelet count. The clumping is associated with EDTA anticoagulant. What is the most appropriate next step?

A quality control program plots a control result that falls more than two standard deviations from the mean, and the next run shows a result also more than two standard deviations on the same side. According to Westgard rules, which rule has most likely been violated?

A wound culture grows a gram-positive coccus in clusters that is catalase positive, coagulase positive, and able to ferment mannitol on mannitol salt agar producing a yellow color. Which organism is most consistent with these results?

A laboratory performs a latex agglutination test for rheumatoid factor. The latex particles are coated with which substance so they will agglutinate when rheumatoid factor is present?

A urine reagent strip is read after sitting much longer than the manufacturer recommended time. Which result is most likely to be falsely affected by this delayed reading?

A direct antiglobulin test (DAT) is performed on a newborn with suspected hemolytic disease of the fetus and newborn. A positive DAT in this setting indicates which of the following?

An automated analysis reports an erythrocyte sedimentation rate that is markedly elevated. Which physiologic or pathologic factor most directly increases the ESR by promoting red cell rouleaux formation?

A patient with suspected acute pancreatitis has laboratory testing ordered. Which pair of serum enzymes is most commonly elevated and used to support the diagnosis of acute pancreatitis?