Liver Uptake Transporter Assays

The liver uptake transporter assays provide a means to assess whether a test compound is a potential substrate or inhibitor of specific drug transporters within the liver. We provide liver transporter assays for small molecule formulations such as pharmaceuticals, industrial chemicals, and consumer products.

Our liver uptake transporter assays use genetically modified versions of the immortalized human liver cell line HepaRG™, created with our proprietary CompoZr® zinc finger nuclease (ZFN) technology.

Hepatic uptake transporters (e.g., NTCP, OATPs, OATs and OCTs) are essential in the hepatic uptake of drugs from sinusoidal blood into the liver and are known to play a role in hepatic clearance and drug-drug interactions. In particular, OATP1B1 and OATP1B3 have been described as clinically relevant transporters, and European and U.S. regulatory agencies recommend the assessment of potential interactions with these transporters for all new drugs. HepaRG cells are known to express hepatic uptake and efflux drug transporters, and have recently been used to study drug uptake as an alternative to primary human hepatocytes.

We have developed a control HepaRG cell line with enhanced functional activity (clone 5F) as well as OATP1B1 and OATP1B3 knockout cell lines which can be used to screen for interactions with these hepatic uptake transporters. Studies are carried out in sandwich cultured HepaRG cells, and the amount of test substance accumulated in the cells is measured at the end of the incubation period by LC-MS/MS. Confirmation that a drug is a substrate for OATP1B1/1B3 can be achieved by comparing results in the control cells with the knockout cell lines.

 Liver Uptake Transporter Assay Protocol

Test System HepaRG liver cell line, clone 5F (human)
HepaRG liver cell line, OATP1B1 KO
HepaRG liver cell line, OATP1B3 KO
Test Compound Concentration 10 µM, or custom
Replicates 3
Assay Length 10 minutes
Controls Vehicle (0.1% DMSO)
Estrone 3-sulfate
Analysis Method LC-MS/MS



  • Kotani N et al. (2012) Expression and transport function of drug uptake transporters in differentiated HepaRG cells, Mol Pharm 9, 3434-3441
  • Le Vee M et al. (2013) Polarized expression of drug transporters in differentiated human hepatoma HepaRG cells, Toxicol In Vitro 27, 1979-1986
  • Szabo M et al. (2013) Comparison of human hepatoma HepaRG cells with human and rat hepatocytes in uptake transport assays in order to predict a risk of drug induced hepatotoxicity, PLoS One 8(3):e59432