NEWEST Certified Phlebotomy Technician
(PBT) American Society for Clinical
Pathology EXAM | ULTIMATE EXAM WITH
CORRECT ANSWERS AND RATIONALES
FOR CERTIFICATION SUCCESS
1. A phlebotomist must collect a specimen from a
patient who has a left mastectomy and an
intravenous (IV) line in the right arm. Where should
the phlebotomist collect the blood?
A) Below the IV line in the right arm
B) Above the IV line in the right arm
C) From the left arm (mastectomy side)
D) From a vein in the foot
Correct answer: B
Rationale: Blood should never be drawn from the
mastectomy side due to risk of lymphedema. The
preferred site is above the IV line in the opposite arm
after turning off the IV for two minutes and discarding
a small amount of blood. Drawing below the IV will
produce contaminated, diluted specimens.
,2. Which of the following is the correct order of draw
for blood collection tubes using a standard
evacuated tube system?
A) Blood culture, light blue, red, green, lavender,
gray
B) Lavender, green, red, light blue, gray, blood
culture
C) Light blue, red, green, lavender, gray, blood
culture
D) Red, light blue, green, lavender, gray, blood
culture
Correct answer: A
Rationale: The order of draw is: blood culture bottles
(yellow), light blue (coagulation), red/speckled
(serum), green (heparin), lavender (EDTA), gray
(glucose). This sequence prevents cross-
contamination of tube additives.
3. A phlebotomist is preparing to collect a blood
specimen for a complete blood count (CBC) and a
prothrombin time (PT). Which tube should be filled
first?
A) Lavender top
B) Light blue top
,C) Red top
D) Green top
Correct answer: B
Rationale: The light blue top (sodium citrate for
coagulation studies) must be collected before the
lavender top (EDTA for CBC) to prevent EDTA
contamination, which would cause inaccurate PT
results.
4. The additive in a light blue-topped blood collection
tube is:
A) EDTA
B) Sodium citrate
C) Lithium heparin
D) Sodium fluoride
Correct answer: B
Rationale: Light blue-topped tubes contain sodium
citrate, which binds calcium and is used for
coagulation studies such as PT, PTT, and fibrinogen.
The tube must be filled completely to maintain the
proper 9:1 blood-to-additive ratio.
5. The additive in a lavender-topped (purple) blood
collection tube is:
, A) Sodium polyanethol sulfonate (SPS)
B) EDTA (ethylenediaminetetraacetic acid)
C) Lithium heparin
D) Sodium citrate
Correct answer: B
Rationale: Lavender-topped tubes contain EDTA, an
anticoagulant that binds calcium, preserving cellular
morphology. They are used for hematology tests
such as CBC, ESR, and blood typing.
6. The additive in a green-topped blood collection
tube is:
A) EDTA
B) Sodium citrate
C) Lithium or sodium heparin
D) Sodium fluoride
Correct answer: C
Rationale: Green-topped tubes contain heparin
(lithium, sodium, or ammonium), which inhibits
thrombin formation. They are used for plasma
chemistry tests such as electrolytes, ammonia, and
some STAT tests.
(PBT) American Society for Clinical
Pathology EXAM | ULTIMATE EXAM WITH
CORRECT ANSWERS AND RATIONALES
FOR CERTIFICATION SUCCESS
1. A phlebotomist must collect a specimen from a
patient who has a left mastectomy and an
intravenous (IV) line in the right arm. Where should
the phlebotomist collect the blood?
A) Below the IV line in the right arm
B) Above the IV line in the right arm
C) From the left arm (mastectomy side)
D) From a vein in the foot
Correct answer: B
Rationale: Blood should never be drawn from the
mastectomy side due to risk of lymphedema. The
preferred site is above the IV line in the opposite arm
after turning off the IV for two minutes and discarding
a small amount of blood. Drawing below the IV will
produce contaminated, diluted specimens.
,2. Which of the following is the correct order of draw
for blood collection tubes using a standard
evacuated tube system?
A) Blood culture, light blue, red, green, lavender,
gray
B) Lavender, green, red, light blue, gray, blood
culture
C) Light blue, red, green, lavender, gray, blood
culture
D) Red, light blue, green, lavender, gray, blood
culture
Correct answer: A
Rationale: The order of draw is: blood culture bottles
(yellow), light blue (coagulation), red/speckled
(serum), green (heparin), lavender (EDTA), gray
(glucose). This sequence prevents cross-
contamination of tube additives.
3. A phlebotomist is preparing to collect a blood
specimen for a complete blood count (CBC) and a
prothrombin time (PT). Which tube should be filled
first?
A) Lavender top
B) Light blue top
,C) Red top
D) Green top
Correct answer: B
Rationale: The light blue top (sodium citrate for
coagulation studies) must be collected before the
lavender top (EDTA for CBC) to prevent EDTA
contamination, which would cause inaccurate PT
results.
4. The additive in a light blue-topped blood collection
tube is:
A) EDTA
B) Sodium citrate
C) Lithium heparin
D) Sodium fluoride
Correct answer: B
Rationale: Light blue-topped tubes contain sodium
citrate, which binds calcium and is used for
coagulation studies such as PT, PTT, and fibrinogen.
The tube must be filled completely to maintain the
proper 9:1 blood-to-additive ratio.
5. The additive in a lavender-topped (purple) blood
collection tube is:
, A) Sodium polyanethol sulfonate (SPS)
B) EDTA (ethylenediaminetetraacetic acid)
C) Lithium heparin
D) Sodium citrate
Correct answer: B
Rationale: Lavender-topped tubes contain EDTA, an
anticoagulant that binds calcium, preserving cellular
morphology. They are used for hematology tests
such as CBC, ESR, and blood typing.
6. The additive in a green-topped blood collection
tube is:
A) EDTA
B) Sodium citrate
C) Lithium or sodium heparin
D) Sodium fluoride
Correct answer: C
Rationale: Green-topped tubes contain heparin
(lithium, sodium, or ammonium), which inhibits
thrombin formation. They are used for plasma
chemistry tests such as electrolytes, ammonia, and
some STAT tests.
