RT Journal Article SR Electronic(1) A1 Friedmann, Rosa A1 Epstein, C.YR 1951 T1 The Assay of the Antibiotic Nisin by Means of a Reductase (Resazurin) test JF Microbiology, VO 5 IS 5 SP 830 OP 839 DO https://doi.org/10.1099/00221287-5-5-830 PB Microbiology Society, SN 1465-2080, AB Summary: The familiar resazurin test used in milk testing has been adapted to the estimation of nisin, using a fast-growing strain of Streptococcus cremoris as test organism. The reproducibility and accuracy of this test compares favourably with the many other assay methods for nisin which use Strep. agalactiae as test organism. Results may be obtained in less than an hour as compared with 15–48 hr. in the other tests and are a measure of bactericidal power only. Aseptic technique during the actual assay procedure is unnecessary. Methods were devised to ensure a suitable standard inoculum, which is imperative for this test. As little as 0·5 unit nisin ml, may be estimated., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-5-5-830