Ready-to-Assay™ GPCR frozen cells are designed for simple, rapid assays with no requirement for intensive cell culturing. Eurofins DiscoverX Products LLC. has optimized the freezing conditions to provide cells with high viability and functionality post-thaw.  Simply thaw the cells and resuspend them in media, dispense cell suspension into assay plates and, following overnight recovery follow the protocol to run the assay. Chem-1 Parental Control Frozen Cells are designed for use as a negative control alongside our GPCR-expressing Ready-to-Assay Frozen Cells in the Chem-1 background. Chem-1 cells lack endogenous expression of most GPCRs, although they endogenously express trypsin and thrombin receptors that may be used to confirm responsiveness of the cells in calcium assays.