A portion of a 30 ml sample of milk is tested for general inhibition by a starter activity test and if positive results are obtained the remainder of the sample is subjected to a disc assay test for antibiotics and specific chemical test for quaternary ammonium compounds and sulfonamides. All of these tests are readily adaptable to a systematic laboratory procedure. Their significance and limitations are discussed.
*The authors wish to express their appreciation to A. H. Robertson, Department of Agriculture & Markets, New York, for his interest and advice in regard to this problem and to C. W. Christensen, Difco Co., Detroit, Mich., for his technical assistance relative to the disc assay method.
Mr. G. J. Silverman is a graduate assistant at Cornell University. He was born in New York City and after serving in the United States Armed Forces, was accepted at Cornell University, receiving a B.S. and M.S. in Dairy Industry and hopes to eventually obtain a Ph.D. from this institution.