THE ESTIMATION OF PENICILLIN IN MILK

Abstract
Summary: A simple test for the estimation of 001‐0‐30 i.u. of penicillin per ml. of milk is proposed, based on the inhibition of a strain of Streptococcus thermophilics 'BC Fairly accurate assessments are obtained in 21 hr. using 2:3:5 triphenyltetrazolium chloride (TTC) as indicator, or more accurate results in 4 hr. using titratable acidities.