[Microbiological assay of pantothenic acid in rat liver using Tetrahymena].

Microbiological Assay of Pantothenic Acid in Rat Liver using Tetrahymena. The quantitative determination of total pantothenic acid in rat liver using Tetrahymena was carried out in the same way as a microbiological assay. The strain selected was Tetrahymena thermophila grown on rat liver. Inoculum was obtained from a commercial medium. The assay medium consisted of a dry powder to be rehydrated and heated to boiling, and then adjusted to pH 7. Liver pantothenic acid was extracted by autolysis. Tetrahymena use made one accustomed to a biological reagent easy to manipulate but with complex nutritional requirements. Consequently the organism should be more extensively used for nutritional or toxicological studies.