Medical Technologist Test Medical Technologist Knowledge 4

Question 1

The direct antiglobulin test (DAT) detects:

Accepted Answer

Antibodies or complement coating patient's red blood cells in vivo

Answer

The DAT uses anti-human globulin reagent to detect IgG antibodies or complement components already bound to RBCs in vivo.

Question 2

Which culture medium is selective and differential for gram-negative enteric organisms, inhibiting gram-positive bacteria?

Accepted Answer

MacConkey agar

Answer

MacConkey agar contains bile salts and crystal violet to inhibit gram-positive bacteria while differentiating lactose-fermenting from non-fermenting gram-negative rods.

Question 3

In a manual differential WBC count, 100 cells are counted. If 68 are neutrophils and the total WBC is 5,000/µL, the absolute neutrophil count (ANC) is:

Accepted Answer

3,400/µL

Answer

ANC = 68% × 5,000/µL = 3,400/µL, which is within the normal adult reference range.

Question 4

Which electrolyte abnormality is most consistent with a patient who has been vomiting repeatedly?

Accepted Answer

Hypokalemia and metabolic alkalosis

Answer

Repeated vomiting causes loss of HCl and fluid, leading to hypokalemia and metabolic alkalosis.

Question 5

The beta-lactamase test on a Staphylococcus aureus isolate is performed to determine:

Accepted Answer

Penicillin resistance

Answer

Beta-lactamase production confers resistance to penicillin by hydrolyzing its beta-lactam ring; this guides antibiotic selection.

Medical Technologist Test Practice Test

Medical Technologist Test Practice Test

Medical Technologist Test Medical Technologist Knowledge 4