@article{mbs:/content/journal/micro/10.1099/00221287-6-1-2-30, author = "Heatley, N. G. and Kelly, B. K. and Smith, Nancy", title = "The Assay of Micrococcin, an almost Insoluble Antibiotic", journal= "Microbiology", year = "1952", volume = "6", number = "1-2", pages = "30-40", doi = "https://doi.org/10.1099/00221287-6-1-2-30", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-6-1-2-30", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", abstract = "Summary: The difficulties of assaying micrococcin by the usual microbiological methods and means of obviating or decreasing some of them are described. Certain detergents have a solubilizing effect on micrococcin and it is possible to assay such ‘solutions’ by hole-plate or other diffusion methods which cannot otherwise be applied. Low results are obtained by this method in crude fermentation liquors, probably because some of the micrococcin is present in a bound form. Ethanolic solutions of micrococcin have a powerful purple fluorescence in ultraviolet light by which amounts of the order of 2·5 μg./ml. may be accurately estimated. Details are given of the procedure, and of the special precautions necessary when micrococcin in broth or tissue is to be estimated. Micrococcin may also be estimated by measuring the absorption in ethanolic solution at 345 mμ., at which wavelength E 1 cm. 1 % = 177·5.", }