ExpressPlus UGT Inhibition Using Recombinant Enzymes and LC-MS/MS

This assay is used to assess the potential of a test compound to inhibit individual human UDP-glucuronosyltransferase (UGT) isoforms

Catalog number EA432

Required from Customer



Assay System

Assay Conditions

Assay QC


  1. The results from this assay are sent to the customer in the ExpressPlus report format, which may include graphical representations of data and comparison with historical data for reference compounds.
  2. Percent inhibition is calculated from the amount of metabolite formed in the presence of test compound relative to that formed in the absence of test compound, based on the peak area response ratio (PARR): % Inhibition = [(PARR without test compound) - (PARR with test compound) / (PARR without test compound)] x 100%.
  3. Pricing is based on screening for inhibition of at least five UGT isoforms per test compound.
UGT Isoforms, Probe Substrates and Metabolites
UGT Probe Substrate Conc. (µM) Metabolite
UGT1A1, UGT1A3, UGT1A6, UGT1A9, UGT2B7 7-HFC 100 7-HFCG
          7-HFC = 7-hydroxy-4-trifluoromethylcoumarin 7-HFCG = 7-HFC glucuronide TFP = trifluoperazine TFPG = TFP glucuronide
Positive Control Inhibitors for Standard (hepatic) UGT Isoforms
UGT Positive Control Inhibitor
UGT1A1 Bilirubin
UGT1A3 Buprenophine
UGT1A4 Hecogenin
UGT1A6 1-Naphthol
UGT1A9 Niflumic acid
UGT2B7 Diclofenac


  1. The customer must specify: • the concentration of test compound • which UGT isoforms to assay