Each vial contains 200 g of lyophilized peptide derived from the human EP2 receptor sequence (C-terminal amino acids 335-358; SLRTQDATQTSCSTQSDASKQADL).1 This peptide was used as an antigen for production of the EP2 receptor polyclonal antibody (Catalog No. 101750) and can be used in conjunction with this antibody to block protein-antibody complex formation during immunochemical analysis for the EP2 receptor. The biological effects of prostaglandin E2 (PGE2) are mediated through interaction with four distinct membrane-bound G-protein coupled EP receptors: EP1, EP2, EP3, and EP4.2,3 Binding of PGE2 to the EP2 receptor results in an increase in adenylate cyclase activity with a subsequent increase in cAMP.1,4 Pharmacologically, EP2 receptors mediate relaxation of smooth muscle and are distinguished from EP4 receptors by their sensitivity to the EP2 receptor selective agonist butaprost.2,3,1 The human EP2 receptor is comprised of 358 amino acids with a molecular mass of approximately 40,000.1 A band at 53 kDa is detected in most samples by western blotting. mRNA for the EP2 receptor is expressed in a variety of tissues including lung, placenta, spleen, intestine, kidney, and sensory neuron.1,4,5