FIELD: analytical biochemistry. SUBSTANCE: solution of carbocyanine dye (1-ethyl-2-[3-(1-ethylnaphtho-[1,2] -thiazoline-2-ylidene)- -2-methylpropenyl] -naphtho-[1,2-d]-thiazolium bromide) in formamide and buffer solution are added directly to lipopolysaccharide sample to be tested and sodium sulfite is added. Dye solution can be stored in cooling for 3-4 weeks without inactivation. Addition of unstable solution of ascorbic acid to dye solution is excluded. Colored complex of lipopolysaccharide with carbocyanine dye is stable for 1-5 h and its optical density is decreased by 3-5%, not above. Method can be used for quantitative determination of bacterial lipopolysaccharides during production of medicinal immunobiological preparations. Method ensures to analyze a lot of samples. EFFECT: simplified procedure, increased stability. 1 dwg
