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Free MLT Practice Questions

10 free, exam-style Medical Laboratory Technician (MLT) practice questions with answers and explanations. No signup required. Work through them below, then take the full free MLT practice test to study every exam domain.

The MLT exam has 100 questions and runs 2 hours 30 minutes.

These 10 free MLT questions are organized by exam domain, so you can see how each part of the Medical Laboratory Technician blueprint is tested. Reveal the answer and explanation under each question.

Domain 1: Blood Banking (15-20%)

Question 1

A patient with diabetic ketoacidosis (DKA) would have which blood gas pattern?

  1. pH ↑, pCO₂ ↑, HCO₃⁻ ↑
  2. pH ↓, pCO₂ ↓, HCO₃⁻ ↓
  3. pH ↓, pCO₂ ↑, HCO₃⁻ normal
  4. pH ↑, pCO₂ ↓, HCO₃⁻ ↑
Show answer & explanation

Correct answer: B - pH ↓, pCO₂ ↓, HCO₃⁻ ↓

Domain 2: Chemistry (17-22%)

Question 2

A patient has PT 22 seconds (prolonged), APTT 55 seconds (prolonged), fibrinogen 80 mg/dL (low), D-dimer 8.0 µg/mL (high), platelets 45 × 10⁹/L (low), and schistocytes on smear. This pattern is MOST consistent with:

  1. Warfarin overdose
  2. Hemophilia A
  3. DIC
  4. Von Willebrand disease
Show answer & explanation

Correct answer: C - DIC

Question 3

A patient has MCV 65 fL, RBC count 6.5 × 10⁶/µL (high-normal), and RDW 12.5% (normal). This pattern is MOST consistent with:

  1. Beta-thalassemia minor
  2. Anemia of chronic disease
  3. Sideroblastic anemia
  4. Iron deficiency anemia
Show answer & explanation

Correct answer: A - Beta-thalassemia minor

Question 4

A 4-year-old child presents with fatigue, bruising, and bone pain. The CBC shows WBC 45 × 10⁹/L with 80% blasts that are MPO negative, PAS positive (block pattern), and TdT positive. The MOST likely diagnosis is:

  1. Infectious mononucleosis with atypical lymphocytes
  2. Acute myeloid leukemia with myelodysplastic changes
  3. Acute lymphoblastic leukemia (ALL)
  4. Chronic myeloid leukemia in blast crisis
Show answer & explanation

Correct answer: C - Acute lymphoblastic leukemia (ALL)

Domain 3: Hematology (17-22%)

Question 5

An antibody reacts at IAT (37°C/AHG phase) and is nonreactive with enzyme-treated cells. The antibody is MOST likely in which system?

  1. Kidd
  2. Rh
  3. Duffy or MNS (enzymes destroy Fy-a, Fy-b, M, N, S)
  4. Lewis
Show answer & explanation

Correct answer: C - Duffy or MNS (enzymes destroy Fy-a, Fy-b, M, N, S)

Question 6

The KEY laboratory test that distinguishes TACO (transfusion-associated circulatory overload) from TRALI is:

  1. Direct antiglobulin test (DAT)
  2. Platelet count and morphology
  3. Hemoglobin and hematocrit levels
  4. B-type natriuretic peptide (BNP)
Show answer & explanation

Correct answer: D - B-type natriuretic peptide (BNP)

Domain 4: Microbiology (17-22%)

Question 7

Neisseria gonorrhoeae and N. meningitidis are both oxidase-positive gram-negative diplococci. They are differentiated by sugar utilization: N. gonorrhoeae ferments:

  1. Glucose ONLY (not maltose)
  2. Maltose ONLY (not glucose)
  3. Lactose and sucrose ONLY
  4. Glucose, maltose, and lactose
Show answer & explanation

Correct answer: A - Glucose ONLY (not maltose)

Domain 5: Urinalysis/Other Body Fluids (5-10%)

Question 8

In synovial fluid analysis, needle-shaped crystals that are negatively birefringent (appear YELLOW when parallel to the slow ray of the compensator) indicate:

  1. Gout (monosodium urate crystals)
  2. Septic arthritis (bacterial infection)
  3. Pseudogout (calcium pyrophosphate)
  4. Osteoarthritis (cartilage degeneration)
Show answer & explanation

Correct answer: A - Gout (monosodium urate crystals)

Domain 6: Immunology (5-10%)

Question 9

A patient's panel shows: HBsAg negative, anti-HBs negative, anti-HBc IgM positive, anti-HBc IgG positive. This pattern indicates:

  1. Recent vaccination with detectable core antibodies
  2. Window period of acute hepatitis B infection
  3. Chronic hepatitis B carrier state
  4. Resolved hepatitis B infection with immunity
Show answer & explanation

Correct answer: B - Window period of acute hepatitis B infection

Domain 7: Laboratory Operations (5-10%)

Question 10

Two consecutive QC values both exceed +2 SD on the SAME side of the mean. Which Westgard rule is violated?

  1. R-4s (reject)
  2. 1-3s (warning)
  3. 1-2s (warning)
  4. 2-2s (reject)
Show answer & explanation

Correct answer: D - 2-2s (reject)

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