Possibility for error in FDA diffusion assays.
Computational procedures specified for the FDA single-dose diffusion assay for antibiotics may cause substantial error in estimated sample potency. An unrecognized mistake in reference solution concentration is the source of error. It is caused by correcting responses from standard and sample plates differently. The error can be avoided by correcting both standard and sample responses to the observed reference response.
D000900:Anti-Bacterial Agents / Q000032:analysis*; D001412:Bacillus subtilis / Q000187:drug effects; D001681:Biological Assay; D002506:Cephalexin / Q000032:analysis / Q000494:pharmacology; D004058:Diffusion; D008722:Methods; D014481:United States; D014486:United States Food and Drug Administration
D000900:Anti-Bacterial Agents; D002506:Cephalexin