Mouse Anti-Rabbit IgG (Conformation Specific) (L27A9) mAb only reacts with native IgG and does not bind to the denatured and reduced rabbit IgG heavy chain or light chain. When performing immunopreciptiation (IP) followed by western blotting, the denatured rabbit IgG light and heavy chains of the primary antibody used for IP run at approximately 25 and 50 kD, respectively, on the subsequent western blot and can often obscure bands of proteins that have similar molecular weights. Using Mouse Anti-Rabbit IgG (Conformation Specific) (L27A9) mAb as a secondary antibody will eliminate this problem.