KOH String Test is a rapid bedside/lab test used to differentiate Gram-negative from Gram-positive bacteria without performing Gram stain. 🧪 How it works: Mix a colony with 3% KOH on a slide Gently lift with a loop or stick 🧬 Result interpretation: 🧵 String formation (viscous, sticky thread) → Gram-negative ✅ 👉 Cell wall breaks → DNA released ❌ No string → Gram-positive ⚡ Why it’s useful: Faster than Gram stain Helpful when Gram stain is unclear Great for teaching & quick screening 📌 Rememb

Allens Test- ❓Who still does this test routinely before starting an arterial line? 🩸 It is performed to assess the patience of the radial and ulnar arteries of the hand. Helps determine the suitability of collateral circulation before performing procedures such as radial artery cannulation or radial artery harvesting for graft. Explanation: Allen’s test is performed by oclosing the radial and ulnar arteries of the hand while the patient closes the fist. The patient is then asked to open their h