Evaluation of Agar Dilution Method for Determination of Sensitivity of Bacteria to Antibiotics. ∗

Conclusions

1. The agar dilution and tube dilution methods of determining bacterial sensitivity are equally reliable. 2. Aureomycin-containing plates can be stored for 3 weeks without loss of potency; plates containing penicillin, bacitracin, streptomycin, chloramphenicol, and terramycin can be stored for 4 weeks without loss of potency. 3. The agar diffusion method of sensitivity determination is not fully reliable, as shown by poor correlation of the results obtained by that method and the tube dilution method of testing with some antibiotics.