NAPTP Specimen Processing and Handling

Question 1

What is the maximum time a whole blood specimen should sit before being centrifuged if serum is required?

Accepted Answer

60 minutes

Answer

Whole blood specimens should be allowed to clot for 30–60 minutes before centrifugation; exceeding 2 hours can compromise analyte integrity, but 60 minutes is the standard upper threshold.

Question 2

Which additive tube must NEVER be centrifuged?

Accepted Answer

EDTA (lavender)

Answer

EDTA tubes are collected for whole blood analysis (CBC); centrifuging them separates plasma, destroying the specimen's intended use.

Question 3

A specimen labeled 'STAT' should be processed within how many minutes of collection?

Accepted Answer

15 minutes

Answer

STAT specimens require processing within 15 minutes of collection to ensure rapid, accurate results for urgent clinical decisions.

Question 4

When transporting a cold-sensitive specimen, which method is most appropriate?

Accepted Answer

Transport in ice slurry at 0–4°C

Answer

Cold-sensitive specimens such as ammonia, lactic acid, or ABGs must be transported in an ice slurry (0–4°C) to slow metabolic degradation.

Question 5

Which of the following causes hemolysis in a blood specimen?

Accepted Answer

Forcing blood through a small-gauge needle rapidly

Answer

Forcing blood through a small-gauge needle or syringe at high velocity creates shear stress that ruptures red blood cells, causing hemolysis.

NAPTP - National Association of Phlebotomy Technician Professionals Practice Test

NAPTP - National Association of Phlebotomy Technician Professionals Practice Test

NAPTP Specimen Processing and Handling