Ace the Ivy Tech Microbiology Lab Challenge 2026 – Dive into Discovery and Dominate Test 2!

The disk diffusion method assesses how a bacterial strain responds to antibiotics by looking for zones of inhibition around antibiotic-impregnated disks on an agar plate. The standardized version of this approach is the Kirby-Bauer Test, where the size of the clear area around each disk is compared to reference standards to determine if the bacteria are susceptible, intermediate, or resistant to that antibiotic. This method specifically identifies how well an antibiotic can prevent growth under these conditions, rather than measuring the exact concentration needed to inhibit growth (which is the MIC) or describing whether the drug is inherently bacteriostatic or bactericidal.