T cells respond to peptides presented by the MHC molecules. At the cellular level, each T cell recognize a unique peptide MHC (pMHC) combination where CD8+ and CD4+ T cell subsets are restricted to MHC class I and class II, respectively.

The interaction between the peptide-MHC complex and a cognate TcR is short lived and of low affinity. By way of multimerization of four peptide-MHC molecules on a streaptavidin scaffold, tetramers increases the avidity of the pMHC:TcR interaction by engaging several of the TcRs expressed on a specific T cell thereby stabilizing the interaction. This allows for direct and specific staining of the T cells. pMHC tetramers provide a simple, fast and efficient approach for monitoring and handling specific T cells. Peptide-MHC tetramers can be used to identify specific T cells without further in vitro manipulation, and they allow for a simultaneous evaluation of the differentiation state through co-staining for various cell surface differentiation markers. In addition, peptide-MHC monomers and tetramers can be used to purify and manipulate the specific T cells.

Our MHC molecules are biotinylated; hence all our pMHC monomers can be tetramerize through the biotin-streptavidin interaction.

Available formulations: The peptide-MHC complexes are available as monomers (biotinylated) or tetramers. The monomers have a longer shelf life and a higher flexibility with respect to your staining scheme i.e you can make your own tetramers with the streptavidin label(s) of your choice, (including metal labels for CyTOF analysis).

The tetramers are available with Phycoerythrin (PE) and allophycocyanin (APC) fluorochromes.

The monomers and tetramers are available as:
Catalog peptide-Class I and peptide-Class II complexes covering a range of known epitopes. These have a delivery time of 1-2 weeks.

Custom peptide-Class I and peptide-Class II complexes using a peptide of your choice. See our available MHC class I molecules, and our available MHC class II molecules
For your design of custom peptide-MHC class I and II complexes, we recommend that you use predictors (e.g. one from the NetMHC series).