Respiratory syncytial virus (RSV) fusion (F) protein is a surface glycoprotein encoded by the F gene in RSV RNA.{67138} It is synthesized as an inactive precursor protein, F0, that undergoes proteolytic cleavage to release the F1 and F2 subunits, which are joined together by two disulfide bonds.{67139} Mature RSV F protein is composed of an N-terminal fusion peptide (FP), two heptad repeats (HRs), a transmembrane domain, and a cytoplasmic tail and assembles into homotrimers on the virus surface.{67138} Upon insertion of the FP in the target cell membrane, the HRs form a six-helical bundle (6-HB) that enables RSV to fuse with the target cell. RSV F protein is highly conserved between RSV subtypes A and B with approximately 90% amino acid identities.{67140} RSV is the most common causative agent of pediatric lower respiratory tract infections.{67141} Cayman's RSV F Protein Chimeric Monoclonal Antibody was produced recombinantly from the original humanized RSHZ19 antibody sequence, substituting the mouse antigen-binding domain with the rabbit IgG1 antigen-binding domain, and can be used for ELISA and in functional assays. The RSHZ19 antibody was generated by fusing human IgG1 constant domains to the antigen-binding domain of a mouse anti-RSV F protein monoclonal antibody.{44025}