Corning® Gentest™ Hepatocyte Transporter Suspension Assay Kit, 100 Tests per Kit, 1/Pack by Corning Life Sciences

It contains the critical components for stopping transport activity and separating hepatocytes from the uptake solution for 100 assay data points. This kit is a convenient in vitro method for measuring transporter activity in cryopreserved or fresh hepatocyte suspensions (Current Drug Metabolism 8:341 [2007]). The filtration assay depends on an oil layer or “cushion” which serves as a barrier between the reaction mix (hepatocytes and substrate) and a lower layer of 2N NaOH. After the incubation period, the assay mixture (containing cells, substrate, and buffer) is layered on top of the oil cushion and centrifuged briefly. The hepatocytes pass through the filtration oil into the lower layer of NaOH, which serves to solubilize the cell membrane and release the radiolabeled substrate.

The oil layer barrier prevents the aqueous assay mix containing free radiolabeled substrate from entering the NaOH layer.The lower portion of the microcentrifuge tube, containing the cells and transported substrate, is cut away from the upper layer, mixed with scintillation cocktail, and measured by scintillation counting. The assay is carried out at both 4°C and 37°C; the 4°C sample serves as the negative control (disintegrations per minute [DPM] at 4°C represents nonspecific binding).