Prostaglandin F2α-biotin (PGF2α-biotin) is an affinity probe which allows PGF2α to be detected through an interaction with the biotin ligand. PGF2α-biotin was designed to allow PGF2α to be detected in complexes with transmembrane receptors and/or nucleic acid or protein binding partners. It is thus a tool to be used in the general elucidation of the mechanism of action of PGs.