A Simple Clinical Method for the Assay of Penicillin in Body Fluids

Many of the methods for penicillin assay were devised and used primarily for testing solutions during the production of penicillin and are not easily applicable to the determination of titers of body fluids in patients under treatment. These have been reviewed by Foster and Woodruff,1the classic test of Florey2being in most common use. Of the studies made on body fluids, the method described by Rammelkamp3involving the use of serial broth dilutions and a strain of hemolytic streptococcus was used by Rammelkamp and Keefer.4Rosenberg and Sylvester5have used Foster's method6of serial broth dilution with Staphylococcus aureus and turbidimetric measurements, while Romansky and Rittman7have used a method described by Rake and Jones8based on the property of the inhibition of hemolysin production of streptococci by penicillin. The procedure to be described here is believed to be simpler than