Prostaglandin E Receptor EP1/PTGER1 (extracellular) Blocking Peptide (#BLP-PR063) is the original antigen used for immunization during Anti-Prostaglandin E Receptor EP1 (PTGER1) (extracellular) Antibody (#APR-063) generation. The blocking peptide binds and ‘blocks’ Anti-Prostaglandin E Receptor EP1/PTGER1 (extracellular) primary antibody, this makes it a good negative reagent control to help confirm antibody specificity in western blot and immunohistochemistry applications. This control is also often called a pre-adsorption control.