Anti-CREB pS133 Antibody - Western Blot. Anti-CREB pS133 was used to detect phosphorylated CREB by western blot. Recombinant His-tagged human CREB was produced in E. coli and purified by metal affinity chromatography. An aliquot of purified CREB was phosphorylated in-vitro using Protein Kinase A and ATP. western blot of control (-) and in-vitro phosphorylated CREB (+) was used to show that the antibody reacts specifically with the phosphorylated form. Pan reactive CREB (# LS-C19089) reacts equally with both non-phosphorylated and phosphorylated CREB (not shown). Detection occurs using a 1:500 dilution of antibody followed by 1:5000 dilution of HRP Goat-a-Rabbit IgG with visualization via ECL. Film exposure was approximately 1. Other detection systems will yield similar results. Personal Communication, Boss, J., Emory University School of Medicine, Atlanta, GA.