NCMA Basic Laboratory Procedures and Specimen Handling 2

Question 1

What is the correct temperature range for refrigerating urine specimens awaiting analysis?

Accepted Answer

2°C to 8°C

Answer

Urine specimens must be refrigerated at 2°C to 8°C to preserve cellular elements and prevent bacterial overgrowth if not analyzed within one hour of collection.

Question 2

Which type of specimen tube contains EDTA as an anticoagulant?

Accepted Answer

Lavender/purple top

Answer

Lavender (purple) top tubes contain EDTA (ethylenediaminetetraacetic acid), which chelates calcium to prevent clotting, making them ideal for complete blood counts (CBC).

Question 3

What does a quality control (QC) chart help the medical assistant monitor in the laboratory?

Accepted Answer

Accuracy and precision of test results over time

Answer

QC charts (Levey-Jennings charts) plot control values over time to identify trends, shifts, or random errors that may indicate problems with reagents, instruments, or technique.

Question 4

Which specimen is used for a fasting blood glucose test?

Accepted Answer

Serum or plasma from a venipuncture after 8–12 hours of fasting

Answer

A fasting blood glucose requires the patient to abstain from food and caloric beverages for 8–12 hours prior to collection; serum or plasma is then obtained by venipuncture.

Question 5

What is the purpose of the chain of custody procedure for laboratory specimens?

Accepted Answer

To document every person who handled the specimen to ensure legal integrity

Answer

Chain of custody documents every individual who collected, transferred, or handled a specimen, ensuring legal defensibility particularly for drug testing, forensic, or workplace samples.

NCMA - National Certified Medical Assistant Practice Test

NCMA - National Certified Medical Assistant Practice Test

NCMA Basic Laboratory Procedures and Specimen Handling 2