S1PR1/EDG1 (extracellular) Blocking Peptide (#BLP-SR011) is the original antigen used for immunization during Anti-S1PR1 (EDG1) (extracellular) Antibody (#ASR-011) generation. The blocking peptide binds and ‘blocks’ Anti-S1PR1/EDG1 (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.