Test your expertise in enteric pathogen isolation with our XLD Agar (Xylose Lysine Deoxycholate) Mock Test! This 30-question quiz evaluates your ability to:
✔ Interpret Colony Morphology:
- Salmonella (red with black centers)
- Shigella (red/pink, no H₂S)
- Proteus (yellow, swarming)
✔ Master Selective/Differential Principles:
- Xylose fermentation → Yellow to red color shift
- Lysine decarboxylation → Alkaline reaction
- Deoxycholate inhibition → Gram-positive suppression
✔ Follow CLSI Protocols:
- Incubation (35-37°C, 18-24h)
- QC strains (Salmonella Typhimurium ATCC 14028)
✔ Troubleshoot Common Issues:
- Overgrowth by Pseudomonas
- Weak H₂S production
🔬 Key Features:
✓ Image-Based Questions – Analyze real XLD agar plates
✓ Detailed Explanations – Learn CLSI/FDA guidelines
✓ Instant Scoring – Benchmark your performance
✓ Mobile-Optimized – Study on-the-go
🎯 Perfect For:
- Medical Lab Technicians (MLT/MLS certification)
- Microbiology Students (ASCP, USMLE prep)
- Public Health Investigators
- “XLD agar Salmonella vs Shigella MCQs”
- “How to read H₂S production on XLD”
- “Best incubation time for XLD agar”
- “CLSI guidelines for stool culture media”
Read Full Article: Xylose Lysine Deoxycholate (XLD) agar FAQs and MCQs






