Question 1

Which of the following statements best describes the function of a tourniquet during venipuncture?

Accepted Answer

It slows down the return of blood to the heart, aiding in vein location.

Question 2

A light-blue–topped vacuum tube is used for coagulation studies. What is the primary additive in this tube, and why is it critical to fill the tube to the indicated volume?

Accepted Answer

Sodium citrate; underfilling alters the blood-to-additive ratio, causing inaccurate results.

Question 3

Which color-coded tube is most appropriate for collecting a specimen for a blood glucose test that requires glycolytic inhibition?

Accepted Answer

Gray-topped tube containing sodium fluoride.

Question 4

A phlebotomist is preparing to collect blood for a platelet count and blood smear. Which tube and additive should be used to preserve cell morphology and prevent platelet aggregation?

Accepted Answer

Purple-topped tube containing EDTA.

Question 5

What is the mechanism by which oxalates, citrates, and EDTA prevent blood clotting in collection tubes?

Accepted Answer

They remove calcium by forming insoluble calcium salts.

Question 6

Which of the following is a major safety advantage of passive needle shielding devices in blood collection?

Accepted Answer

The safety shield automatically covers the needle after blood collection, reducing needlestick risk.

Question 7

A blood specimen for HLA typing and donor compatibility testing should be collected in which type of tube?

Accepted Answer

Yellow-topped tube containing acid citrate-dextrose (ACD).

Question 8

Why is it important to gently invert blood collection tubes containing anticoagulants immediately after collection?

Accepted Answer

To ensure proper mixing and prevent formation of clots and microclots.

Question 9

Which of the following substances can interfere with clinical testing of blood analytes and should be considered during specimen collection?

Accepted Answer

Hemolysis, lipemia, and presence of anticoagulant preservatives.

Question 10

A phlebotomist is collecting blood from a patient with fragile veins. Which equipment is preferred to minimize vein damage and accidental needlesticks?

Accepted Answer

Safety butterfly needle blood collection set.

Question 11

What is the correct procedure for disposing of used needles and other sharps after blood collection?

Accepted Answer

Place them in a rigid, leak-proof, plastic sharps container labeled as biohazardous waste.

Question 12

Which equation best represents the relationship between needle gauge and diameter?

Accepted Answer

$$d \propto \frac{1}{g}$$, where $$d is $$diameter and $$g is $$gauge number.

Question 13

A blood specimen for a STAT chemistry test requiring rapid serum separation should be collected in which tube?

Accepted Answer

Orange-topped tube with thrombin-based clot activator and gel.

Question 14

Which of the following is NOT a recommended practice for glove use during blood collection?

Accepted Answer

Washing and reusing gloves between patients.

Question 15

A phlebotomist is preparing to collect blood for a lead test. Which tube should be used?

Accepted Answer

Tan-topped tube containing EDTA.

Question 16

Why is it important to avoid using expired vacuum tubes for blood collection?

Accepted Answer

Expired tubes may lose vacuum, resulting in insufficient blood volume and inaccurate test results.

Question 17

Which of the following best describes the function of a serum separation tube (SST) during centrifugation?

Accepted Answer

It forms a polymer barrier that separates serum from fibrin and cells.

Question 18

A phlebotomist is collecting blood for an erythrocyte sedimentation rate (ESR) test. Which tube and additive should be used?

Accepted Answer

Black-topped tube with buffered sodium citrate.

Question 19

When performing a heel stick on an infant, what is the recommended maximum penetration depth to avoid bone injury according to CLSI guidelines?

Accepted Answer

$$\u003c 2.0 \ \mathrm{mm}$$

Question 20

Which of the following is a real-world consequence of not filling a vacuum tube to the indicated volume line during blood collection?

Accepted Answer

The blood-to-additive ratio will be inaccurate, leading to erroneous laboratory results.

Blood Collection Equipment and Safety in Phlebotomy: Study Notes for Personal Health Students

Study Guide - Practice Questions

Study Guide - Flashcards