Kidney epithelial cells from the proximal part of the tubulus are and essential tool to specifically asses nephrotoxicity in vitro. ciPTEC cells are conditionally immortalized proximal tubular epithelial cells developed by the Radbound University Nijmegen (NL). The activity of two kidney specific organic anion transporters (OAT1 and OAT3) have been reconstituted in the cells by recombinant expression. acCELLerate provides ciPTEC assay ready cells which have been differentiated before cryopreservation. The cells are ready to use in nephrotoxicity testing without prior cultivation or further differentiation. They are provided in single-use alliquots of 5 million cells/vial and come with suitable amounts of recovery buffer and assay medium.