2026 MLA Exam Prep: Medical Laboratory Assistant
Practice Questions, Answer Rationales, Specimen
Collection, Processing, Laboratory Safety & Patient
Care Study Guide
Domain 1: Patient Accessioning and Specimen Collection (Questions 1–25)
Question 1. Which of the following is the correct order of draw for multiple blood
collection tubes during venipuncture?
A) Serum tube, citrate tube, heparin tube, EDTA tube
B) Blood culture tube, citrate tube, serum tube, heparin tube, EDTA tube,
glycolytic inhibitor tube
C) EDTA tube, citrate tube, serum tube, heparin tube
D) Heparin tube, EDTA tube, citrate tube, serum tube
Rationale: The CLSI-recommended order of draw is: blood culture tube or bottle,
sodium citrate tube (light blue), serum tubes including those with clot activator and
gels (red, red-speckled, gold), heparin tube (green), EDTA tube (lavender), and
glycolytic inhibitor tube (gray).
Question 2. What is the primary purpose of the order of draw?
A) To reduce patient discomfort
B) To prevent carryover contamination from tube additives that could alter
test results
C) To speed up the collection process
D) To ensure all tubes are filled equally
Rationale: The order of draw is critical because additive carryover during tube
changes can alter test results. When healthcare professionals adhere to the order of
draw, patients are more likely to be treated according to results that truly reflect
their physiology.
,Question 3. Which of the following is an acceptable patient identifier for specimen
collection?
A) Patient's room number
B) Patient's full name and date of birth
C) Patient's bed number
D) Patient's diagnosis
Rationale: At least two unique patient identifiers must be used, such as the
patient's full name and date of birth. Bed numbers and room numbers are not
acceptable identifiers because they change frequently.
Question 4. What should an MLA do if a patient's identity cannot be verified
before specimen collection?
A) Proceed with collection using the room number
B) Do not collect the specimen until identity is verified
C) Ask another patient to confirm the name
D) Collect the specimen and label it later
Rationale: Patient identification must be verified immediately before any
specimen collection procedure using two patient identifiers. If identity cannot be
verified, the MLA must not proceed until proper identification is established.
Question 5. Which specimen collection tube is used for coagulation testing?
A) Red top tube
B) Light blue top tube
C) Lavender top tube
D) Green top tube
Rationale: Light blue top tubes contain sodium citrate and are used for
coagulation testing. They must be filled to the correct volume to ensure the proper
anticoagulant-to-blood ratio.
Question 6. What is the recommended site for capillary puncture in adults?
,A) The tip of the index finger
B) The lateral or palmar surface of the ring finger
C) The earlobe
D) The thumb
Rationale: The palmar or lateral surface of the tip of the finger (preferably the ring
finger) is the most common site for capillary puncture in adults because it is
accessible and less painful than other sites.
Question 7. Which of the following is a contraindication to venipuncture?
A) The patient is taking aspirin
B) The patient has an active intravenous line in the arm
C) The patient is fasting
D) The patient has a history of anemia
Rationale: An active IV line in the arm is a contraindication to venipuncture
because of the risk of contamination from IV fluids and medications. Venipuncture
should be performed on the opposite arm or below the IV site with provider
approval.
Question 8. What is the maximum time a tourniquet should be left in place during
venipuncture?
A) 30 seconds
B) 1 minute
C) 5 minutes
D) 10 minutes
Rationale: The tourniquet should be left in place no longer than 1 minute.
Prolonged application results in partial stasis of blood and changes many
quantitative values of blood components.
Question 9. Which blood collection tube contains EDTA as an anticoagulant?
A) Red top tube
B) Lavender top tube
, C) Green top tube
D) Gray top tube
Rationale: Lavender top tubes contain EDTA, which chelates calcium and
prevents clotting. EDTA tubes are used for hematology testing, including CBC and
blood bank testing.
Question 10. What is the correct procedure for performing a capillary puncture?
A) Squeeze the finger firmly to obtain blood
B) Puncture the skin with one quick, continuous stroke on the lateral aspect of
the finger
C) Puncture the center of the fingertip
D) Use the thumb for puncture
Rationale: The skin should be punctured with one quick, continuous, and
deliberate stroke on the lateral aspect of the finger. Squeezing the finger can cause
hemolysis and tissue fluid contamination.
Question 11. Which of the following is a sign that a patient may experience a
syncopal episode during venipuncture?
A) Pallor and diaphoresis
B) Hypertension and tachycardia
C) Flushed skin and warmth
D) Increased appetite
Rationale: Pallor, diaphoresis, nausea, and dizziness are common signs of an
impending syncopal episode. The MLA should stop the procedure, lower the
patient's head, and apply a cold compress.
Question 12. What is the maximum depth of a capillary puncture in an adult?
A) 1 mm
B) 3 mm
C) 5 mm
D) 10 mm
Practice Questions, Answer Rationales, Specimen
Collection, Processing, Laboratory Safety & Patient
Care Study Guide
Domain 1: Patient Accessioning and Specimen Collection (Questions 1–25)
Question 1. Which of the following is the correct order of draw for multiple blood
collection tubes during venipuncture?
A) Serum tube, citrate tube, heparin tube, EDTA tube
B) Blood culture tube, citrate tube, serum tube, heparin tube, EDTA tube,
glycolytic inhibitor tube
C) EDTA tube, citrate tube, serum tube, heparin tube
D) Heparin tube, EDTA tube, citrate tube, serum tube
Rationale: The CLSI-recommended order of draw is: blood culture tube or bottle,
sodium citrate tube (light blue), serum tubes including those with clot activator and
gels (red, red-speckled, gold), heparin tube (green), EDTA tube (lavender), and
glycolytic inhibitor tube (gray).
Question 2. What is the primary purpose of the order of draw?
A) To reduce patient discomfort
B) To prevent carryover contamination from tube additives that could alter
test results
C) To speed up the collection process
D) To ensure all tubes are filled equally
Rationale: The order of draw is critical because additive carryover during tube
changes can alter test results. When healthcare professionals adhere to the order of
draw, patients are more likely to be treated according to results that truly reflect
their physiology.
,Question 3. Which of the following is an acceptable patient identifier for specimen
collection?
A) Patient's room number
B) Patient's full name and date of birth
C) Patient's bed number
D) Patient's diagnosis
Rationale: At least two unique patient identifiers must be used, such as the
patient's full name and date of birth. Bed numbers and room numbers are not
acceptable identifiers because they change frequently.
Question 4. What should an MLA do if a patient's identity cannot be verified
before specimen collection?
A) Proceed with collection using the room number
B) Do not collect the specimen until identity is verified
C) Ask another patient to confirm the name
D) Collect the specimen and label it later
Rationale: Patient identification must be verified immediately before any
specimen collection procedure using two patient identifiers. If identity cannot be
verified, the MLA must not proceed until proper identification is established.
Question 5. Which specimen collection tube is used for coagulation testing?
A) Red top tube
B) Light blue top tube
C) Lavender top tube
D) Green top tube
Rationale: Light blue top tubes contain sodium citrate and are used for
coagulation testing. They must be filled to the correct volume to ensure the proper
anticoagulant-to-blood ratio.
Question 6. What is the recommended site for capillary puncture in adults?
,A) The tip of the index finger
B) The lateral or palmar surface of the ring finger
C) The earlobe
D) The thumb
Rationale: The palmar or lateral surface of the tip of the finger (preferably the ring
finger) is the most common site for capillary puncture in adults because it is
accessible and less painful than other sites.
Question 7. Which of the following is a contraindication to venipuncture?
A) The patient is taking aspirin
B) The patient has an active intravenous line in the arm
C) The patient is fasting
D) The patient has a history of anemia
Rationale: An active IV line in the arm is a contraindication to venipuncture
because of the risk of contamination from IV fluids and medications. Venipuncture
should be performed on the opposite arm or below the IV site with provider
approval.
Question 8. What is the maximum time a tourniquet should be left in place during
venipuncture?
A) 30 seconds
B) 1 minute
C) 5 minutes
D) 10 minutes
Rationale: The tourniquet should be left in place no longer than 1 minute.
Prolonged application results in partial stasis of blood and changes many
quantitative values of blood components.
Question 9. Which blood collection tube contains EDTA as an anticoagulant?
A) Red top tube
B) Lavender top tube
, C) Green top tube
D) Gray top tube
Rationale: Lavender top tubes contain EDTA, which chelates calcium and
prevents clotting. EDTA tubes are used for hematology testing, including CBC and
blood bank testing.
Question 10. What is the correct procedure for performing a capillary puncture?
A) Squeeze the finger firmly to obtain blood
B) Puncture the skin with one quick, continuous stroke on the lateral aspect of
the finger
C) Puncture the center of the fingertip
D) Use the thumb for puncture
Rationale: The skin should be punctured with one quick, continuous, and
deliberate stroke on the lateral aspect of the finger. Squeezing the finger can cause
hemolysis and tissue fluid contamination.
Question 11. Which of the following is a sign that a patient may experience a
syncopal episode during venipuncture?
A) Pallor and diaphoresis
B) Hypertension and tachycardia
C) Flushed skin and warmth
D) Increased appetite
Rationale: Pallor, diaphoresis, nausea, and dizziness are common signs of an
impending syncopal episode. The MLA should stop the procedure, lower the
patient's head, and apply a cold compress.
Question 12. What is the maximum depth of a capillary puncture in an adult?
A) 1 mm
B) 3 mm
C) 5 mm
D) 10 mm
