RMA Microbiology and Specimen Collection 2 — Questions and Answers
Question 1: What is the recommended order of draw for venipuncture when collecting multiple tubes?
- Blood culture, coagulation, serum, heparin, EDTA, glycolytic inhibitor (Correct answer)
- EDTA, serum, heparin, coagulation, blood culture
- Serum, EDTA, heparin, blood culture, coagulation
- Heparin, EDTA, serum, coagulation, blood culture
Correct answer: Blood culture, coagulation, serum, heparin, EDTA, glycolytic inhibitor
The correct order is blood culture first, then coagulation (light blue), serum (red/SST), heparin (green), EDTA (lavender), and glycolytic inhibitor (gray).
Question 2: Which specimen is the gold standard for diagnosing a urinary tract infection?
- Clean-catch midstream urine (Correct answer)
- First morning random void
- 24-hour urine collection
- Catheterized urine left at room temperature overnight
Correct answer: Clean-catch midstream urine
A clean-catch midstream specimen minimizes contamination from skin and genital flora, making it ideal for urine culture.
Question 3: A throat swab for strep testing should be collected from which area?
- The tonsils and posterior pharynx (Correct answer)
- The inner cheek and gums
- The tongue surface only
- The anterior nares
Correct answer: The tonsils and posterior pharynx
The swab should contact the tonsillar areas and posterior pharynx where Streptococcus is most likely present.
Question 4: What term describes microorganisms that require oxygen to grow?
- Aerobes (Correct answer)
- Anaerobes
- Facultative anaerobes
- Microaerophiles
Correct answer: Aerobes
Aerobes require oxygen for metabolism and growth.
Question 5: Which container additive is used to preserve a stool specimen for ova and parasite examination?
- Formalin or PVA fixative (Correct answer)
- Sodium fluoride
- EDTA
- Sodium citrate
Correct answer: Formalin or PVA fixative
Formalin and polyvinyl alcohol (PVA) preserve parasite morphology in stool specimens.
Question 6: What is the proper technique for collecting a nasopharyngeal specimen?
- Insert the swab gently along the nasal floor to the nasopharynx and rotate (Correct answer)
- Swab only the tip of the nostril
- Wipe the outside of the nose
- Insert the swab into the throat through the mouth
Correct answer: Insert the swab gently along the nasal floor to the nasopharynx and rotate
The swab is passed straight back along the nasal floor until it reaches the nasopharynx, then rotated to collect cells.
Question 7: Why must blood culture sites be cleaned with antiseptic before collection?
- To prevent skin flora from contaminating the culture and causing false positives (Correct answer)
- To make the vein easier to see
- To numb the puncture site
- To speed up clotting
Correct answer: To prevent skin flora from contaminating the culture and causing false positives
Proper skin antisepsis prevents normal skin bacteria from contaminating the culture and producing false-positive results.
RMA Microbiology and Specimen Collection 2
What is the recommended order of draw for venipuncture when collecting multiple tubes?