BILE ACIDS.Twelve different types of bile acids are typically found in mammals, among them two primary types are cholic acid and chenodeoxycholic acid. These can be dehydroxylated into secondary bile acids. Finally, these four can be conjugated to either taurine or glycine creating 8 different conjugated bile acids. Bile acid levels in feces, blood, urine, and bile can be used as markers for various diseases such as hyperlipidemia, cholestasis, gall stones, colon cancer, etc. Bile acids also exist in a sulfate salt form known as bile acid-sulfates. Sulfation of bile acids increases their solubility and decreases intestinal absorption, thereby enhancing fecal and urinary excretion. This assay does not measure bile acid-sulfates, and measures only the twelve non-sulfated bile acids. This Bile Acid Assay Kit provides a convenient fluorimetric means to measure total bile acids in biological samples. In the assay, 3-beta-hydroxysteroid dehydrogenase reacts with all twelve bile acids, converting NAD to NADH, which reduces a probe to a highly fluorescent product. The resulting fluorescence intensity (lambda ex/em = 530/585 nm) is linear to the bile acid concentration in the sample.