NHCO Phlebotomy Certification Exam
2026/2027 Study Guide | Verified Practice
Questions & Correct Answers with Detailed
Rationales | Comprehensive Phlebotomy
Exam Prep
NHCO PHLEBOTOMY CERTIFICATION EXAM 2026/2027 STUDY GUIDE
Verified Practice Questions & Correct Answers with Detailed Rationales
DOCUMENT OVERVIEW
• This comprehensive 200-question study guide is designed to prepare candidates
for the NHCO Phlebotomy Certification Exam with verified practice questions
covering all major examination domains and competency areas.
• Use this material to assess your knowledge, identify weak areas, and reinforce
critical concepts through detailed rationales that explain the correct answer and the
reasoning behind it.
QUESTIONS
1. When performing venipuncture on a patient with a mastectomy, which arm
should be avoided?
A) The arm on the same side as the mastectomy
B) The arm opposite the mastectomy
C) Either arm is acceptable
D) The arm with the better veins regardless of surgery
E) The upper arm only on either side
CORRECT ANSWER: A) The arm on the same side as the mastectomy
Rationale: Following a mastectomy, the lymphatic system is compromised on the
affected side, which increases the risk of infection and lymphedema. Phlebotomists
,must avoid drawing blood from the arm on the same side as the mastectomy to
prevent complications. This is a critical patient safety consideration in phlebotomy
practice.
2. Which of the following is the correct order of blood collection tubes for a
routine venipuncture draw?
A) Green (heparin), lavender (EDTA), red (serum), light blue (citrate)
B) Light blue (citrate), red (serum), green (heparin), lavender (EDTA)
C) Lavender (EDTA), light blue (citrate), red (serum), green (heparin)
D) Red (serum), light blue (citrate), green (heparin), lavender (EDTA)
E) Light blue (citrate), green (heparin), red (serum), lavender (EDTA)
CORRECT ANSWER: B) Light blue (citrate), red (serum), green (heparin),
lavender (EDTA)
Rationale: The correct order of draw is critical to prevent cross-contamination and
ensure accurate test results. Light blue (citrate) tubes are collected first as they
require a specific blood-to-additive ratio. Red serum tubes follow, then green
(heparin) and finally lavender (EDTA). This sequence minimizes the impact of
additives on subsequent tubes.
3. What is the maximum length of time a tourniquet should be applied during
venipuncture?
A) 1 minute
B) 2 minutes
C) 3 minutes
D) 5 minutes
E) 10 minutes
CORRECT ANSWER: A) 1 minute
,Rationale: A tourniquet should not be applied for more than one minute as
prolonged application can cause hemoconcentration, leading to falsely elevated
test results. Extended tourniquet application also causes patient discomfort and
may lead to hemolysis of the specimen, compromising test accuracy.
4. Which additive is used in lavender-topped tubes?
A) Sodium citrate
B) EDTA (ethylenediaminetetraacetic acid)
C) Potassium oxalate
D) Lithium heparin
E) Sodium heparin
CORRECT ANSWER: B) EDTA (ethylenediaminetetraacetic acid)
Rationale: Lavender-topped tubes contain EDTA as an anticoagulant. EDTA is a
chelating agent that binds calcium and magnesium, preventing blood clotting.
These tubes are primarily used for complete blood count (CBC) and other
hematology tests where preservation of blood cells is essential.
5. What is the primary purpose of the dermal puncture (capillary collection)?
A) To collect large volumes of blood for multiple tests
B) To collect small amounts of blood from infants, elderly, or difficult venipuncture
patients
C) To prevent bruising in patients on anticoagulant therapy
D) To reduce the risk of hemolysis
E) To obtain specimens that do not require anticoagulants
CORRECT ANSWER: B) To collect small amounts of blood from infants, elderly,
or difficult venipuncture patients
, Rationale: Dermal puncture (capillary collection) is used when small volumes of
blood are needed, particularly from infants whose veins are too small for
venipuncture, elderly patients with fragile veins, or patients with difficult-to-access
venous systems. This method is less traumatic and provides an effective alternative
for specimen collection.
6. Which site is the preferred location for capillary puncture in infants?
A) The heel
B) The finger
C) The earlobe
D) The top of the foot
E) The inner wrist
CORRECT ANSWER: A) The heel
Rationale: The heel is the preferred site for capillary puncture in infants because it
has a good blood supply, is easily accessible, and is less likely to cause infection
compared to other sites. The puncture should be made on the medial or lateral
portion of the heel, avoiding the central area where nerves and arteries are located.
7. What is the normal fasting blood glucose range for an adult patient?
A) 50-70 mg/dL
B) 70-100 mg/dL
C) 100-150 mg/dL
D) 150-200 mg/dL
E) 200-250 mg/dL
CORRECT ANSWER: B) 70-100 mg/dL
2026/2027 Study Guide | Verified Practice
Questions & Correct Answers with Detailed
Rationales | Comprehensive Phlebotomy
Exam Prep
NHCO PHLEBOTOMY CERTIFICATION EXAM 2026/2027 STUDY GUIDE
Verified Practice Questions & Correct Answers with Detailed Rationales
DOCUMENT OVERVIEW
• This comprehensive 200-question study guide is designed to prepare candidates
for the NHCO Phlebotomy Certification Exam with verified practice questions
covering all major examination domains and competency areas.
• Use this material to assess your knowledge, identify weak areas, and reinforce
critical concepts through detailed rationales that explain the correct answer and the
reasoning behind it.
QUESTIONS
1. When performing venipuncture on a patient with a mastectomy, which arm
should be avoided?
A) The arm on the same side as the mastectomy
B) The arm opposite the mastectomy
C) Either arm is acceptable
D) The arm with the better veins regardless of surgery
E) The upper arm only on either side
CORRECT ANSWER: A) The arm on the same side as the mastectomy
Rationale: Following a mastectomy, the lymphatic system is compromised on the
affected side, which increases the risk of infection and lymphedema. Phlebotomists
,must avoid drawing blood from the arm on the same side as the mastectomy to
prevent complications. This is a critical patient safety consideration in phlebotomy
practice.
2. Which of the following is the correct order of blood collection tubes for a
routine venipuncture draw?
A) Green (heparin), lavender (EDTA), red (serum), light blue (citrate)
B) Light blue (citrate), red (serum), green (heparin), lavender (EDTA)
C) Lavender (EDTA), light blue (citrate), red (serum), green (heparin)
D) Red (serum), light blue (citrate), green (heparin), lavender (EDTA)
E) Light blue (citrate), green (heparin), red (serum), lavender (EDTA)
CORRECT ANSWER: B) Light blue (citrate), red (serum), green (heparin),
lavender (EDTA)
Rationale: The correct order of draw is critical to prevent cross-contamination and
ensure accurate test results. Light blue (citrate) tubes are collected first as they
require a specific blood-to-additive ratio. Red serum tubes follow, then green
(heparin) and finally lavender (EDTA). This sequence minimizes the impact of
additives on subsequent tubes.
3. What is the maximum length of time a tourniquet should be applied during
venipuncture?
A) 1 minute
B) 2 minutes
C) 3 minutes
D) 5 minutes
E) 10 minutes
CORRECT ANSWER: A) 1 minute
,Rationale: A tourniquet should not be applied for more than one minute as
prolonged application can cause hemoconcentration, leading to falsely elevated
test results. Extended tourniquet application also causes patient discomfort and
may lead to hemolysis of the specimen, compromising test accuracy.
4. Which additive is used in lavender-topped tubes?
A) Sodium citrate
B) EDTA (ethylenediaminetetraacetic acid)
C) Potassium oxalate
D) Lithium heparin
E) Sodium heparin
CORRECT ANSWER: B) EDTA (ethylenediaminetetraacetic acid)
Rationale: Lavender-topped tubes contain EDTA as an anticoagulant. EDTA is a
chelating agent that binds calcium and magnesium, preventing blood clotting.
These tubes are primarily used for complete blood count (CBC) and other
hematology tests where preservation of blood cells is essential.
5. What is the primary purpose of the dermal puncture (capillary collection)?
A) To collect large volumes of blood for multiple tests
B) To collect small amounts of blood from infants, elderly, or difficult venipuncture
patients
C) To prevent bruising in patients on anticoagulant therapy
D) To reduce the risk of hemolysis
E) To obtain specimens that do not require anticoagulants
CORRECT ANSWER: B) To collect small amounts of blood from infants, elderly,
or difficult venipuncture patients
, Rationale: Dermal puncture (capillary collection) is used when small volumes of
blood are needed, particularly from infants whose veins are too small for
venipuncture, elderly patients with fragile veins, or patients with difficult-to-access
venous systems. This method is less traumatic and provides an effective alternative
for specimen collection.
6. Which site is the preferred location for capillary puncture in infants?
A) The heel
B) The finger
C) The earlobe
D) The top of the foot
E) The inner wrist
CORRECT ANSWER: A) The heel
Rationale: The heel is the preferred site for capillary puncture in infants because it
has a good blood supply, is easily accessible, and is less likely to cause infection
compared to other sites. The puncture should be made on the medial or lateral
portion of the heel, avoiding the central area where nerves and arteries are located.
7. What is the normal fasting blood glucose range for an adult patient?
A) 50-70 mg/dL
B) 70-100 mg/dL
C) 100-150 mg/dL
D) 150-200 mg/dL
E) 200-250 mg/dL
CORRECT ANSWER: B) 70-100 mg/dL
