Free CCBMA Laboratory Procedures and Specimen Collection Questions and Answers — Questions and Answers
Question 1: When performing a venipuncture, what is the correct order of draw if a light blue, a lavender, and a red top tube are needed?
- Red, Lavender, Light Blue
- Light Blue, Red, Lavender (Correct answer)
- Lavender, Red, Light Blue
- Red, Light Blue, Lavender
Correct answer: Light Blue, Red, Lavender
The correct order of draw is critical to prevent cross-contamination of additives between tubes. The standard order is: blood cultures, light blue (coagulation), red/gold (serum), green (heparin), lavender (EDTA), and gray (glycolytic inhibitor). Therefore, the correct sequence is light blue, red, then lavender.
Question 2: The additive in a lavender-topped blood collection tube is:
- Sodium Citrate
- Heparin
- EDTA (Correct answer)
- Potassium Oxalate
Correct answer: EDTA
Lavender (or purple) top tubes contain the anticoagulant Ethylenediaminetetraacetic acid (EDTA). EDTA works by binding to calcium in the blood, which prevents the coagulation cascade and preserves the blood cells for hematology tests like a complete blood count (CBC).
Question 3: In a routine urinalysis, what does the specific gravity of the urine measure?
- The presence of glucose
- The pH level
- The concentration of dissolved particles (Correct answer)
- The amount of red blood cells
Correct answer: The concentration of dissolved particles
Specific gravity measures the concentration of dissolved solutes in the urine, reflecting the kidney's ability to concentrate urine. A high specific gravity indicates concentrated urine (possible dehydration), while a low specific gravity indicates dilute urine.
Question 4: Which of the following is considered a CLIA-waived test that a medical assistant can perform?
- Blood culture and sensitivity
- Pap smear analysis
- Complete blood count (CBC)
- Rapid streptococcus test (Correct answer)
Correct answer: Rapid streptococcus test
CLIA-waived tests are simple laboratory examinations and procedures that have an insignificant risk of an erroneous result. A rapid streptococcus test, or 'rapid strep,' is a common example of a CLIA-waived test performed in many medical offices.
Question 5: How should a medical assistant handle a blood specimen for a bilirubin test?
- It must be frozen immediately
- It must be protected from light (Correct answer)
- It must be kept at body temperature
- It must be centrifuged within 10 minutes
Correct answer: It must be protected from light
Bilirubin is photosensitive, meaning it breaks down when exposed to light. To ensure an accurate test result, specimens for bilirubin testing must be protected from light by wrapping the tube in foil or using an amber-colored collection tube.
Question 6: The most common and preferred site for routine venipuncture in adults is the:
- Basilic vein
- Cephalic vein
- Median cubital vein (Correct answer)
- Dorsal hand veins
Correct answer: Median cubital vein
The median cubital vein, located in the antecubital fossa (the bend of the elbow), is the most common site for venipuncture. It is typically large, well-anchored, and close to the surface, making it the easiest and safest vein to access.
Question 7: When collecting a throat swab for a rapid strep test, the medical assistant should swab the:
- Tongue and cheeks
- Uvula only
- Posterior pharynx and tonsils (Correct answer)
- Roof of the mouth
Correct answer: Posterior pharynx and tonsils
To obtain an adequate sample for a throat culture or rapid strep test, the swab should be directed to the posterior pharynx and the tonsillar areas. It is important to avoid touching the tongue, cheeks, or uvula to prevent contamination of the sample.
Free CCBMA Laboratory Procedures and Specimen Collection Questions and Answers
When performing a venipuncture, what is the correct order of draw if a light blue, a lavender, and a red top tube are needed?