AMT MLT Exam Bank 2025 | 2 Accurate Currently
Testing Exam Versions – 200 Latest Q&A with
Rationales | Medical Laboratory Technician
Certification Study Guide
SECTION 1: BLOOD COLLECTION & PROCESSING (Questions
1–25)
Question 1
A phlebotomist collects a lavender-top tube for a CBC, then a light blue-top tube for
PT/INR. According to CLSI standards, is this order of draw acceptable?
A. Yes, lavender before light blue is the correct order
B. Yes, any order is acceptable as long as tubes are mixed
C. No, the light blue tube must be collected before the lavender tube
D. No, both tubes cannot be drawn in the same session
Answer: C
Rationale: Order of draw requires the light blue (sodium citrate) tube to be collected before
the lavender (EDTA) tube to prevent contamination with EDTA, which falsely prolongs
coagulation times. The standard order is: blood culture bottles → light blue → red/serum
→ green (heparin) → lavender (EDTA) → gray (fluoride/oxalate) .
,Question 2
The tourniquet should be applied approximately how many inches above the
venipuncture site?
A. 1–2 inches
B. 3–4 inches
C. 5–6 inches
D. 7–8 inches
Answer: B
Rationale: The tourniquet should be applied 3–4 inches above the puncture site to allow
adequate venous filling without causing excessive pressure or discomfort. Applying too
high may reduce effectiveness, while applying too low may interfere with the puncture site
.
Question 3
Which vein is the first choice for routine venipuncture in adult patients?
A. Basilic vein
B. Cephalic vein
C. Dorsal hand vein
D. Median cubital vein
Answer: D
Rationale: The median cubital vein is the preferred site because it is typically large, well-
anchored, less likely to roll, and has fewer adjacent nerves, reducing patient discomfort .
,Question 4
A lavender-top tube contains which additive and is used for which test?
A. Sodium citrate – coagulation studies
B. EDTA – hematology studies (CBC)
C. Heparin – chemistry tests
D. Sodium fluoride – glucose testing
Answer: B
Rationale: Lavender (purple) top tubes contain EDTA (ethylenediaminetetraacetic acid),
which chelates calcium and is used for hematology testing (CBC, blood smears) because it
preserves cell morphology .
Question 5
Which blood collection tube additive acts as an antiglycolytic agent to preserve
glucose?
A. Heparin
B. EDTA
C. Sodium fluoride
D. Sodium citrate
Answer: C
Rationale: Sodium fluoride inhibits glycolysis by blocking the enzyme enolase, preserving
glucose levels for up to 24 hours. Gray top tubes contain sodium fluoride and potassium
oxalate .
, Question 6
What is the minimum blood-to-anticoagulant ratio required for a light blue top tube?
A. 1:1
B. 2:1
C. 9:1
D. 4:1
Answer: C
Rationale: Light blue top tubes require a 9:1 blood-to-anticoagulant ratio. Underfilling or
overfilling can alter coagulation test results by affecting calcium binding and clot
formation .
Question 7
A technologist receives a blood specimen labeled with only the patient's last name. The
requisition lists full name and date of birth. The specimen is otherwise properly filled.
Which action is required?
A. Add the missing identifiers from the requisition and proceed with testing
B. Process the specimen because the last name matches the requisition
C. Call the floor and accept verbal confirmation of identity
D. Reject the specimen and request recollection with complete patient identification
Answer: D
Rationale: Laboratory specimens must have at least two unique patient identifiers that
match the requisition. A single name is insufficient; the specimen must be rejected and
recollected to prevent misidentification errors .
Testing Exam Versions – 200 Latest Q&A with
Rationales | Medical Laboratory Technician
Certification Study Guide
SECTION 1: BLOOD COLLECTION & PROCESSING (Questions
1–25)
Question 1
A phlebotomist collects a lavender-top tube for a CBC, then a light blue-top tube for
PT/INR. According to CLSI standards, is this order of draw acceptable?
A. Yes, lavender before light blue is the correct order
B. Yes, any order is acceptable as long as tubes are mixed
C. No, the light blue tube must be collected before the lavender tube
D. No, both tubes cannot be drawn in the same session
Answer: C
Rationale: Order of draw requires the light blue (sodium citrate) tube to be collected before
the lavender (EDTA) tube to prevent contamination with EDTA, which falsely prolongs
coagulation times. The standard order is: blood culture bottles → light blue → red/serum
→ green (heparin) → lavender (EDTA) → gray (fluoride/oxalate) .
,Question 2
The tourniquet should be applied approximately how many inches above the
venipuncture site?
A. 1–2 inches
B. 3–4 inches
C. 5–6 inches
D. 7–8 inches
Answer: B
Rationale: The tourniquet should be applied 3–4 inches above the puncture site to allow
adequate venous filling without causing excessive pressure or discomfort. Applying too
high may reduce effectiveness, while applying too low may interfere with the puncture site
.
Question 3
Which vein is the first choice for routine venipuncture in adult patients?
A. Basilic vein
B. Cephalic vein
C. Dorsal hand vein
D. Median cubital vein
Answer: D
Rationale: The median cubital vein is the preferred site because it is typically large, well-
anchored, less likely to roll, and has fewer adjacent nerves, reducing patient discomfort .
,Question 4
A lavender-top tube contains which additive and is used for which test?
A. Sodium citrate – coagulation studies
B. EDTA – hematology studies (CBC)
C. Heparin – chemistry tests
D. Sodium fluoride – glucose testing
Answer: B
Rationale: Lavender (purple) top tubes contain EDTA (ethylenediaminetetraacetic acid),
which chelates calcium and is used for hematology testing (CBC, blood smears) because it
preserves cell morphology .
Question 5
Which blood collection tube additive acts as an antiglycolytic agent to preserve
glucose?
A. Heparin
B. EDTA
C. Sodium fluoride
D. Sodium citrate
Answer: C
Rationale: Sodium fluoride inhibits glycolysis by blocking the enzyme enolase, preserving
glucose levels for up to 24 hours. Gray top tubes contain sodium fluoride and potassium
oxalate .
, Question 6
What is the minimum blood-to-anticoagulant ratio required for a light blue top tube?
A. 1:1
B. 2:1
C. 9:1
D. 4:1
Answer: C
Rationale: Light blue top tubes require a 9:1 blood-to-anticoagulant ratio. Underfilling or
overfilling can alter coagulation test results by affecting calcium binding and clot
formation .
Question 7
A technologist receives a blood specimen labeled with only the patient's last name. The
requisition lists full name and date of birth. The specimen is otherwise properly filled.
Which action is required?
A. Add the missing identifiers from the requisition and proceed with testing
B. Process the specimen because the last name matches the requisition
C. Call the floor and accept verbal confirmation of identity
D. Reject the specimen and request recollection with complete patient identification
Answer: D
Rationale: Laboratory specimens must have at least two unique patient identifiers that
match the requisition. A single name is insufficient; the specimen must be rejected and
recollected to prevent misidentification errors .
