ASPT Blood Collection Equipment & Supplies 2 — Questions and Answers
Question 1: What does 'SST' stand for in the context of blood collection tubes?
- Standard Serum Test
- Serum Separator Tube (Correct answer)
- Sodium Sulfate Tube
- Standard Sample Tube
Correct answer: Serum Separator Tube
SST stands for Serum Separator Tube; it contains a gel barrier that separates serum from cellular components after centrifugation.
Question 2: Which needle gauge is MOST appropriate for venipuncture in a pediatric patient?
- 16 gauge
- 18 gauge
- 20 gauge
- 23 gauge (Correct answer)
Correct answer: 23 gauge
23-gauge (or smaller) needles are preferred for pediatric patients because they cause less trauma and are sized appropriately for smaller, more delicate veins.
Question 3: The gray-top tube contains which combination of additives?
- EDTA and sodium fluoride
- Potassium oxalate and sodium fluoride (Correct answer)
- Heparin and EDTA
- Sodium citrate and thrombin
Correct answer: Potassium oxalate and sodium fluoride
Gray-top tubes contain potassium oxalate (anticoagulant) and sodium fluoride (glycolysis inhibitor) to preserve glucose and lactate levels in the specimen.
Question 4: What is the function of the clot activator found in red or gold-top serum tubes?
- To prevent blood from clotting
- To accelerate the clotting process for serum collection (Correct answer)
- To preserve cellular components intact
- To maintain blood pH during transport
Correct answer: To accelerate the clotting process for serum collection
Clot activators such as silica particles accelerate the natural coagulation cascade, allowing the clot to form quickly so serum can be separated efficiently after centrifugation.
Question 5: Which system allows multiple evacuated tubes to be filled from a single venipuncture without removing the needle?
- Butterfly needle alone
- Evacuated (Vacutainer) multi-sample needle system (Correct answer)
- Insulin syringe
- Capillary tube system
Correct answer: Evacuated (Vacutainer) multi-sample needle system
The evacuated multi-sample needle system (e.g., Vacutainer) uses a double-ended needle and reusable holder, enabling multiple tubes to be collected sequentially from one stick.
Question 6: When selecting a needle gauge for syringe blood collection, the MOST important consideration is:
- Always using the largest gauge to speed collection
- Always using the smallest gauge to minimize discomfort
- Matching gauge to vein size and required sample volume (Correct answer)
- Using 25 gauge for all adult patients
Correct answer: Matching gauge to vein size and required sample volume
Needle gauge should match the vein size and the volume required; too small a gauge risks hemolysis, while too large a gauge causes unnecessary trauma.
Question 7: What is the recommended needle insertion angle for standard adult venipuncture?
- 5–10 degrees
- 15–30 degrees (Correct answer)
- 45–60 degrees
- 60–90 degrees
Correct answer: 15–30 degrees
A 15–30 degree angle allows the needle to enter the vein lumen without penetrating through both walls, ensuring successful blood collection.
ASPT Blood Collection Equipment & Supplies 2
What does 'SST' stand for in the context of blood collection tubes?