The Diazyme Total Bile Acids Assay is a liquid stable system, ready to use for both manual methods and is adaptable for many automated chemistry analyzers. The assay has excellent sensitivity with a linear range from 0 - 180 μM. Diazyme's unique enzyme cycling method amplifies signal for accurate and fast measurement using a small sample up to 50% less than conventional NBT methods making it an excellent choice. The assay has excellent precision with Intra-Assay Precision CV% of <4% and Inter-Assay Precision CV% of <3%. The following substances normally present in serum produced less than 10% deviation at the listed concentrations: Triglycerides at 750 mg/dL, Ascorbic acid at 50 mg/dL, Bilirubin at 50 mg/dL and Hemoglobin at 500 mg/dL. Packaged for optimal operator convenience reagent transfer can be eliminated for most chemistry systems with instrument specific packaging options including RocheTM Hitachi 917 series, Beckman AU (400/600/640/680), Beckman Synchron CX, and DXC.
The reagents of the assay kit are in a stable liquid formulation that allows for ease of use coupled with enhanced performance characteristics. In the presence of Thio-NAD, the enzyme 3-α-hydroxysteroid dehydrogenase (3- α-HSD) converts bile acids to 3-keto steroids and Thio-NADH. The reaction is reversible and 3-α-HSD can convert 3-keto steroids and Thio- NADH to bile acids and Thio-NAD. In the presence of excess NADH, the enzyme cycling occurs efficiently and the rate of formation of Thio-NADH is determined by measuring specific change of absorbance at 405 nm.