Detection of Human IP3R1 by Western Blot and Immunoprecipitation. Samples: Whole cell lysate (5, 15 and 50 ug for WB; 1 mg for IP, 20% of IP loaded) from HeLa cells.  Antibodies: Affinity purified rabbit anti-IP3R1 antibody A302-158A used for WB at 0.04 ug/ml (A) and 0.4 ug/ml (B) and used for IP at 3 ug/mg lysate.  IP3R1 was also immunoprecipitated by rabbit anti-IP3R1 antibody A302-157A, which recognizes an upstream epitope. Detection: Chemiluminescence with exposure times of 30 seconds (A and B).