Human gallbladder tissue membrane protein lysate was prepared by isolating the membrane protein from whole tissue homogenates using a proprietary technique. The human gallbladder tissue was frozen in liquid nitrogen immediately after excision and then stored at -70˚C. The membrane protein is provided in a buffer including HEPES (pH 7.9), MgCl2, KCl, EDTA, Sucrose, Glycerol, sodium deoxycholate, NP-40, and a cocktail of protease inhibitors. For quality control purposes, the isolated gallbladder tissue membrane protein pattern on SDS-PAGE gel is shown to be consistent for each lot by visualization with coomassie blue staining. The isolated gallbladder tissue membrane protein is then Western analyzed by either GAPDH or β-actin antibody to confirm there is no signal or very weak signal.