MLT (ASCP) Practice Questions (2026) — Free Sample Questions with Answers

Answer: B

Group B or group O plasma: Group O plasma contains anti-A and anti-B; its anti-B would attack the patient's group B red cells, so it is not compatible.

Group B or group AB plasma: Correct. The patient is group B. Plasma must lack anti-B: group B plasma has only anti-A, and group AB plasma has neither antibody.

Group O plasma only: This reverses the rule for red cells. Group O is the universal red-cell donor, but O plasma carries anti-B and is the least compatible plasma choice.

Group A or group AB plasma: Group A plasma contains anti-B, which would react with the patient's B antigen. Only the AB part of this choice is acceptable.

Plasma compatibility is the reverse of red-cell compatibility: give plasma that lacks antibodies to the recipient's antigens. Group AB plasma is the universal plasma donor.

Answer: A

Immunoglobulin light chains (Bence Jones protein): Correct. The strip's protein-error-of-indicators pad reacts mainly with albumin. SSA precipitates all proteins, including light chains.

A large amount of albumin from glomerular injury: Albumin is exactly what the strip detects best, so heavy albuminuria would give a positive strip, not a negative one.

Highly alkaline, strongly buffered urine: Very alkaline urine causes a false-positive strip protein, the opposite of the pattern described.

A high concentration of urine glucose: Glucose does not precipitate with SSA and does not cause this strip-negative, SSA-positive pattern.

Strip protein is albumin-selective; SSA detects all proteins. Strip negative with SSA positive points to non-albumin protein such as Bence Jones light chains.

Answer: A

Partially compensated respiratory acidosis: Correct. Low pH with high pCO2 is respiratory acidosis; the raised HCO3⁻ shows renal compensation, but pH is still out of range.

Partially compensated metabolic alkalosis: The pH is acidotic (below 7.35), so the primary disorder cannot be an alkalosis.

Uncompensated metabolic acidosis: Metabolic acidosis would show a low bicarbonate; here HCO3⁻ is high and pCO2 is the abnormal value driving the pH.

Fully compensated respiratory acidosis: Full compensation would bring the pH back into the 7.35–7.45 range; a pH of 7.30 is still abnormal.

Match pH to the value moving the same way: high pCO2 with low pH means respiratory acidosis. Compensation is partial while pH is still outside 7.35–7.45.

Answer: C

26.7 fL: This is the MCH (Hgb × 10 ÷ RBC = 120 ÷ 4.5), which is measured in picograms, not the MCV.

33.3 fL: 33.3 is the MCHC (Hgb ÷ Hct × 100) in g/dL, not the MCV.

80 fL: Correct. MCV = Hct (%) × 10 ÷ RBC (× 10¹²/L) = 360 ÷ 4.5 = 80 fL, at the lower edge of normocytic.

8.0 fL: This leaves out the ×10 factor (36 ÷ 4.5). Hematocrit as a percentage must be multiplied by 10 to give femtoliters.

MCV = Hct × 10 / RBC (fL); MCH = Hgb × 10 / RBC (pg); MCHC = Hgb / Hct × 100 (g/dL).

Answer: C

Immune because of a past natural infection: Past natural infection leaves anti-HBc positive; a negative anti-HBc rules this out.

Chronic hepatitis B infection: Chronic infection requires a positive HBsAg for at least 6 months, which is not present here.

Immune because of hepatitis B vaccination: Correct. The vaccine contains only HBsAg, so vaccinated people develop anti-HBs without anti-HBc.

Acute infection in the window period: The window period shows anti-HBc (IgM) positive with HBsAg and anti-HBs both negative.

Anti-HBs alone = vaccine immunity; anti-HBs + anti-HBc = immunity from past infection; HBsAg positive = current infection.

Answer: C

1-2s; a warning only, so accept the run: One control beyond 2 SD is a warning, but here two controls exceed 2 SD on the same side, which is a rejection rule.

R-4s; random error: R-4s requires one control above +2 SD and another below −2 SD (a range over 4 SD); both controls here are on the positive side.

2-2s; systematic error: Correct. Two control results beyond 2 SD on the same side of the mean violate 2-2s and indicate a shift (systematic error); reject the run.

1-3s; random error: 1-3s requires a single control beyond 3 SD; neither result exceeds 3 SD.

Random error rules: 1-3s and R-4s. Systematic error rules: 2-2s, 4-1s and 10x. Rejection rules mean patient results are not reported until the problem is fixed.