Certified Phlebotomy Technician (CPT) Mock
Examination – Comprehensive Phlebotomy
Practice Questions with Rationales
1. A phlebotomist is preparing to perform a venipuncture on a patient. Which of the following
is the most appropriate way to identify the patient in an inpatient setting?
A. Ask the patient to state their full name and date of birth and compare it to the
requisition.
B. Check the room number and verify the patient’s name on the door.
C. Call the patient by the name listed on the chart and wait for them to nod.
D. Verify the patient’s identity with the attending physician only.
Correct Answer: A
Explanation: Correct patient identification is the most critical step in the pre-analytical
phase of laboratory testing to prevent medical errors. The phlebotomist must use at least
two identifiers, typically the full name and date of birth, which must be cross-referenced
with the identification band and the requisition form. This ensures that the specimen
collected belongs to the correct individual, maintaining clinical accuracy. A common
mistake is relying on room numbers or verbal confirmation without active participation
from the patient.
,2. When performing a routine venipuncture, at what angle should the needle be inserted into
the arm?
A. 15 to 30 degrees
B. 5 to 10 degrees
C. 45 to 60 degrees
D. 90 degrees
Correct Answer: A
Explanation: The standard angle for needle insertion during venipuncture is 15 to 30
degrees to ensure the needle enters the vein lumen without piercing through the back wall.
This range provides the best control and minimize patient discomfort while ensuring
successful access to the superficial veins of the antecubital fossa. Correct angling is
significant for preventing hematomas and nerve injuries. Candidates often make the
mistake of inserting the needle too steeply, which can lead to transfixing the vein.
3. Which of the following tubes should be collected first in the CLSI recommended order of
draw for a multi-tube procedure?
A. Light Blue (Sodium Citrate)
B. Lavender (EDTA)
C. Blood Culture bottles
D. Red (No additive)
,Correct Answer: C
Explanation: Blood cultures must always be collected first to maintain sterility and
prevent contamination from the environment or other tube additives. Following this, the
order generally proceeds from anticoagulants that do not interfere with coagulation to
those that do. Maintaining the order of draw is vital to prevent cross-contamination of
additives which can lead to erroneous test results. A common mistake is drawing a light
blue tube before blood cultures, which introduces a high risk of bacterial contamination
from the non-sterile needle cap.
4. A phlebotomist must collect a specimen for a Prothrombin Time (PT). Which tube color
should be used?
A. Green
B. Light Blue
C. Lavender
D. Gray
Correct Answer: B
Explanation: The Light Blue top tube contains sodium citrate, which is the additive
required for coagulation studies like PT and PTT. Sodium citrate works by binding calcium
in the blood, which preserves the coagulation factors for analysis. Clinical accuracy
depends on the 9:1 ratio of blood to anticoagulant in this tube, requiring it to be filled to the
mark. Candidates frequently fail to fill this tube completely, leading to an ‘over-
anticoagulated’ sample and inaccurate results.
, 5. Which of the following is the primary reason for cleansing the site with 70% isopropyl
alcohol before venipuncture?
A. To sterilize the skin surface completely.
B. To reduce the number of microorganisms on the skin.
C. To numb the site for the patient.
D. To make the vein more visible through the skin.
Correct Answer: B
Explanation: 70% isopropyl alcohol is an antiseptic used to inhibit the growth of bacteria
and reduce the microbial load on the skin before needle insertion. While it does not achieve
true sterilization, it significantly lowers the risk of introducing skin flora into the
bloodstream or the specimen. Proper technique involves circular motion from the center
outward and allowing it to air dry. A common mistake is blowing on the site or fanning it to
dry, which reintroduces contaminants.
6. A patient becomes pale and diaphoretic during a blood draw. What is the most likely
complication occurring?
A. Hematoma
B. Syncope
C. Hemolysis
D. Petechiae
Examination – Comprehensive Phlebotomy
Practice Questions with Rationales
1. A phlebotomist is preparing to perform a venipuncture on a patient. Which of the following
is the most appropriate way to identify the patient in an inpatient setting?
A. Ask the patient to state their full name and date of birth and compare it to the
requisition.
B. Check the room number and verify the patient’s name on the door.
C. Call the patient by the name listed on the chart and wait for them to nod.
D. Verify the patient’s identity with the attending physician only.
Correct Answer: A
Explanation: Correct patient identification is the most critical step in the pre-analytical
phase of laboratory testing to prevent medical errors. The phlebotomist must use at least
two identifiers, typically the full name and date of birth, which must be cross-referenced
with the identification band and the requisition form. This ensures that the specimen
collected belongs to the correct individual, maintaining clinical accuracy. A common
mistake is relying on room numbers or verbal confirmation without active participation
from the patient.
,2. When performing a routine venipuncture, at what angle should the needle be inserted into
the arm?
A. 15 to 30 degrees
B. 5 to 10 degrees
C. 45 to 60 degrees
D. 90 degrees
Correct Answer: A
Explanation: The standard angle for needle insertion during venipuncture is 15 to 30
degrees to ensure the needle enters the vein lumen without piercing through the back wall.
This range provides the best control and minimize patient discomfort while ensuring
successful access to the superficial veins of the antecubital fossa. Correct angling is
significant for preventing hematomas and nerve injuries. Candidates often make the
mistake of inserting the needle too steeply, which can lead to transfixing the vein.
3. Which of the following tubes should be collected first in the CLSI recommended order of
draw for a multi-tube procedure?
A. Light Blue (Sodium Citrate)
B. Lavender (EDTA)
C. Blood Culture bottles
D. Red (No additive)
,Correct Answer: C
Explanation: Blood cultures must always be collected first to maintain sterility and
prevent contamination from the environment or other tube additives. Following this, the
order generally proceeds from anticoagulants that do not interfere with coagulation to
those that do. Maintaining the order of draw is vital to prevent cross-contamination of
additives which can lead to erroneous test results. A common mistake is drawing a light
blue tube before blood cultures, which introduces a high risk of bacterial contamination
from the non-sterile needle cap.
4. A phlebotomist must collect a specimen for a Prothrombin Time (PT). Which tube color
should be used?
A. Green
B. Light Blue
C. Lavender
D. Gray
Correct Answer: B
Explanation: The Light Blue top tube contains sodium citrate, which is the additive
required for coagulation studies like PT and PTT. Sodium citrate works by binding calcium
in the blood, which preserves the coagulation factors for analysis. Clinical accuracy
depends on the 9:1 ratio of blood to anticoagulant in this tube, requiring it to be filled to the
mark. Candidates frequently fail to fill this tube completely, leading to an ‘over-
anticoagulated’ sample and inaccurate results.
, 5. Which of the following is the primary reason for cleansing the site with 70% isopropyl
alcohol before venipuncture?
A. To sterilize the skin surface completely.
B. To reduce the number of microorganisms on the skin.
C. To numb the site for the patient.
D. To make the vein more visible through the skin.
Correct Answer: B
Explanation: 70% isopropyl alcohol is an antiseptic used to inhibit the growth of bacteria
and reduce the microbial load on the skin before needle insertion. While it does not achieve
true sterilization, it significantly lowers the risk of introducing skin flora into the
bloodstream or the specimen. Proper technique involves circular motion from the center
outward and allowing it to air dry. A common mistake is blowing on the site or fanning it to
dry, which reintroduces contaminants.
6. A patient becomes pale and diaphoretic during a blood draw. What is the most likely
complication occurring?
A. Hematoma
B. Syncope
C. Hemolysis
D. Petechiae
