Peptides and Antisera

A peptide is usually too small to elicit a satisfactory immune response in animals. In order to improve immunogenicity, one needs to attach the target peptide to a larger macromolecular structure. While protein carrier conjugation remains the preferred approach, the MAP (multiple antigen peptide) is used in some instances.

Protein carrier conjugation for immunization 

Peptide epitopes are covalently conjugated to a larger carrier protein and the latter conjugate is used as immunogen to generate antisera. 

Standard carrier is (Keyhole Limpet Hemocyanin-KLH), however other proteins are available for conjugation (Bovine Serum Albumin- BSA, Ovalbumin-OVA, etc.).

Multiple antigen peptides 

Multiple antigen peptides (MAP) immunogens contains 8 copies (or 16 copies) of the peptide, synthesized directly on an 8-armed (or 16-armed) branched lysine core. The resulting multimeric is a large macromolecule (10-15 kDa) which has a high molar ratio of peptide antigen to core molecule and does not require further conjugation to a carrier protein. We typically prepare 10-20 mg of these MAP.