CMLA Specimen Collection & Handling 4 — Questions and Answers
Question 1: A 24-hour urine collection is started at 7:00 AM. The patient's first morning void should be:
- Included as the first specimen of the collection
- Discarded, and collection begins with the next void (Correct answer)
- Split between two collection containers
- Refrigerated separately and added at the end
Correct answer: Discarded, and collection begins with the next void
The first morning void is discarded to establish a clean starting point; all subsequent voids for exactly 24 hours are collected.
Question 2: Which of the following conditions makes a specimen unsuitable for most laboratory tests?
- Slight turbidity in a serum tube
- Gross hemolysis of a specimen (Correct answer)
- A small amount of fibrin clot in serum
- Slight yellow discoloration of urine
Correct answer: Gross hemolysis of a specimen
Gross hemolysis releases intracellular contents into the serum/plasma, interfering with many analytes and rendering most results unreliable.
Question 3: What does 'chain of custody' refer to in specimen collection?
- The sequence of tube types collected during phlebotomy
- Documented, unbroken record of specimen handling for legal or forensic specimens (Correct answer)
- The order in which laboratory departments receive specimens
- Standard handoff protocol between nursing and lab staff
Correct answer: Documented, unbroken record of specimen handling for legal or forensic specimens
Chain of custody is a formal, documented process ensuring specimen integrity from collection to reporting for legal, workplace drug testing, or forensic purposes.
Question 4: A blood smear prepared from an EDTA tube should ideally be made within how many hours of collection to preserve accurate WBC morphology?
- Within 1 hour
- Within 2–4 hours (Correct answer)
- Within 12 hours
- Within 24 hours
Correct answer: Within 2–4 hours
Blood smears should be prepared within 2–4 hours of EDTA collection to prevent EDTA-induced morphological changes such as lymphocyte vacuolation.
Question 5: During a capillary puncture, why should the first drop of blood be wiped away?
- It contains too many red blood cells
- It may be contaminated with tissue fluid that can alter results (Correct answer)
- It is required only for glucose testing
- It is used to prime the lancet site
Correct answer: It may be contaminated with tissue fluid that can alter results
The first drop may contain tissue fluid from the puncture, which dilutes the blood and can interfere with test accuracy.
Question 6: Which specimen is required for a fecal occult blood test (FOBT)?
- Random fresh stool collected in a clean dry container (Correct answer)
- Stool collected after a cleansing enema
- A timed 24-hour stool collection
- Stool collected directly into a blood culture bottle
Correct answer: Random fresh stool collected in a clean dry container
FOBT requires a random fresh stool sample collected in a clean, dry container according to the specific card or kit instructions provided.
Question 7: What is the correct depth of a heel stick lancet puncture in a neonate?
- No more than 1.0 mm
- No more than 2.0 mm (Correct answer)
- No more than 3.5 mm
- No more than 5.0 mm
Correct answer: No more than 2.0 mm
Neonatal heel stick depth should not exceed 2.0 mm to avoid bone injury, as the calcaneus can be very close to the skin surface in premature infants.
CMLA Specimen Collection & Handling 4
A 24-hour urine collection is started at 7:00 AM.
The patient's first morning void should be: