Taurolithocholic acid (TLCA) is a taurine-conjugated form of the secondary bile acid lithocholic acid .¹ TLCA (75 μM) increases caspase-3 and -7 activity in Hep3B cells transfected with sodium taurocholate cotransporting peptide (NTCP), but not nontransfected Hep3B cells.² It has been used to induce cholestasis in ex vivo and in vivo animal models of hepatocellular cholestasis.^3,4 Serum levels of TLCA increase approximately 5-fold within two hours during an oral lipid tolerance test in humans.¹ TLCA MaxSpec® standard is a quantitative grade standard of TLCA that has been prepared specifically for mass spectrometry and related applications where quantitative reproducibility is required. The solution has been prepared gravimetrically and is supplied in a deactivated glass ampule sealed under argon. The concentration was verified by comparison to an independently prepared calibration standard. The verified concentration is provided on the certificate of analysis. This TLCA MaxSpec® standard is guaranteed to meet identity, purity, stability, and concentration specifications and is provided with a batch-specific certificate of analysis. Ongoing stability testing is performed to ensure the concentration remains accurate throughout the shelf life of the product. Note: The amount of solution added to the vial is in excess of the listed amount. Therefore, it is necessary to accurately measure volumes for preparation of calibration standards. Follow recommended storage and handling conditions to maintain product quality.