Microbiology and Specimen Collection Flashcards
7 cards from real RMA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Microbiology and Specimen Collection flashcards as text
Which staining method is used to differentiate bacteria into gram-positive and gram-negative groups?
Answer: Gram stain
The Gram stain separates bacteria by cell wall characteristics into gram-positive (purple) and gram-negative (pink/red).
What color do gram-positive bacteria appear after Gram staining?
Answer: Purple/blue
Gram-positive bacteria retain the crystal violet stain and appear purple/blue.
A specimen for anaerobic culture should be handled how?
Answer: Transported quickly with minimal air exposure
Anaerobic organisms die when exposed to oxygen, so specimens must be transported quickly with minimal air exposure.
Which stain is specifically used to identify Mycobacterium tuberculosis?
Answer: Acid-fast (Ziehl-Neelsen) stain
The acid-fast stain detects mycobacteria, which resist decolorization due to their waxy cell wall.
What is the minimum recommended volume for an adult blood culture per bottle to maximize pathogen detection?
Answer: 8-10 mL
Filling each bottle with 8-10 mL of blood optimizes the sensitivity of blood culture detection in adults.
Which type of media supports growth of most bacteria without selecting for specific organisms?
Answer: Enriched/nonselective media like blood agar
Blood agar is an enriched, nonselective medium that supports the growth of a wide range of bacteria.
When a wound culture is ordered, the medical assistant should collect the sample from where?
Answer: Deep within the wound after cleaning the surface
Sampling from deep in the wound after surface cleaning yields the true infecting organisms rather than surface contaminants.