Potent and highly selective inhibitor of glycogen synthase kinase 3 (GSK-3) (IC50 values are 6.7 and 10 nM for GSK-3β and GSK-3α respectively). Exhibits >500-fold selectivity for GSK-3 over closely related kinases; also displays >800-fold selectivity against 45 additional enzymes and receptors. In combination with tranylcypromine (Cat. No. 3852), enables reprogramming of mouse embryonic fibroblasts, transduced by Oct4 and Klf4 only, into iPSCs. Enhances mouse and human ESC self-renewal when used in combination with PD 0325901 (Cat. No. 4192). Allows formation of extended pluripotent stem (EPS) cells in combination with (S)-(+)-Dimethindene maleate (Cat.No. 1425), minocycline hydrochloride (Cat.No. 3268) and human leukemia inhibitory factor. CHIR 99021 synthesized to cGMP guidelines also available.. Purity 98%. MW (observed): 465.34