A new fluorimetric assay for streptothricins.

In strongly acidic medium (70% HClO4) streptothricins form a fluorophore (lambda ex = 312 nm; lambda em = 381 nm) with unknown structure. A fluorimetric determination of pure or crude products and cultures, respectively, was worked out based on this reaction. Concentrations for fluorescence measurements were in the range of 10(-8) - 2 X 10(-7) moles. Interferences of the assay are discussed, a statistical evaluation of results and a comparison between microbiological and fluorimetric findings are given.