Medical Laboratory Technician Exam Medical Laboratory Technician MCQ 1

Question 1

Which tube color is used for coagulation studies such as PT and aPTT?

Accepted Answer

Light blue-top (sodium citrate)

Answer

Light blue-top tubes contain sodium citrate, a calcium-chelating anticoagulant that preserves clotting factors for coagulation testing. The 9:1 blood-to-anticoagulant ratio is critical for accurate results.

Question 2

A urine dipstick shows a positive nitrite result. This finding most likely indicates the presence of:

Accepted Answer

Gram-negative bacteria

Answer

Many gram-negative bacteria (e.g., E. coli) convert dietary nitrates to nitrites via reductase enzymes. A positive nitrite result strongly suggests a urinary tract infection caused by gram-negative organisms.

Question 3

Which of the following white blood cell types is the FIRST to respond to an acute bacterial infection?

Accepted Answer

Neutrophils

Answer

Neutrophils are the primary first-responders in acute bacterial infections. They are phagocytic cells that rapidly migrate to sites of infection, and a left shift (increase in band neutrophils) is a classic laboratory finding.

Question 4

A blood specimen with a hemoglobin of 7.0 g/dL and a mean corpuscular volume (MCV) of 115 fL is most consistent with which type of anemia?

Accepted Answer

Megaloblastic anemia

Answer

Megaloblastic anemia is characterized by a markedly elevated MCV (macrocytosis, typically >100 fL) due to impaired DNA synthesis from vitamin B12 or folate deficiency, resulting in abnormally large red blood cells.

Question 5

Which quality control rule is violated when two consecutive control values fall more than 2 standard deviations on the same side of the mean?

Accepted Answer

Westgard 2-2s rule

Answer

The Westgard 2-2s rule is a rejection rule triggered when two consecutive control measurements exceed 2 SD on the same side of the mean, suggesting a systematic error or bias in the analytical run.

Medical Laboratory Technician Exam Practice Test

Medical Laboratory Technician Exam Practice Test

Medical Laboratory Technician Exam Medical Laboratory Technician MCQ 1