Peptide-Ready MHCs

Ready-to-Use MHCs for Loading Neoantigen Peptides

Load your custom peptide on a peptide-ready MHC to generate your own Peptide-MHC monomer or tetramer.

Fluorescent Labeling

Class I or Class II Allele

Monomer / Tetramer


Functional Peptide-Ready MHCs for Neoantigen Assessment

A crucial step in the neoantigen identification process involves assessing the immune functionality of the antigenic peptide, namely its binding affinity to MHC and reactivity with TCR. KACTUS has launched a range of functional Peptide-Ready MHCs products, which can be used as a ready-to-use loading system for loading antigen peptides, and then form a new complete MHC peptide complex. This streamlined and user-friendly approach can greatly assist your study of neoantigens.

Product List: Peptide-Ready MHCs

Browse our selection of in-stock Peptide-Ready MHC Complexes.

Custom Peptide-Ready MHCs

Choice of MHC-I or MHC-II allele

Monomer, Tetramer, or VLP-MHC Complex

APC-Equivalent, FITC-equivalent, or PE-Labeling


Loaded Peptide-Ready MHCs demonstrate high binding affinity

Applications of Peptide-Ready MHCs

High-throughput screening for specific antigenic peptides

TCR affinity studies and high-throughput characterization 

MHC binding studies

Specific TCR or antigen-reactive T cell screening

Peptide-MHC library construction

Antigen epitope analysis and screening

Neoantigen Peptides

Neoantigens are highly specific targets and ideal targets for immunotherapy. Degraded neoantigen peptides can bind with major histocompatibility complex (MHC) molecules, forming complexes that are subsequently transported to the cell surface. These complexes are recognized by T-cell receptor (TCR), triggering an immune response. MHC polypeptide complexes constitute a category of neoantigen targets, and their distinctive interaction with TCR holds immense importance in the advancement of neoantigen-based immunotherapies, including TCR-T cell therapy, antibody drugs, and tumor vaccines.

Learn More About Neoantigens and Their Role in Next-Gen Immunotherapy

Identification of the affinity of peptide loaded MHC with TCR [1].

MHC Complexes with Loaded Peptide

KACTUS also offers a selection of 100+ Peptide-MHCs as well as Custom Peptide-MHC Production.

Ordering Information

We have a catalog selection of prMHCs in-stock and available to ship. Contact to place an order using a PO or pay via credit card on our website. We also offer custom prMHCs by submitting this form or contacting

To order a custom prMHC, please submit this form or contact

For prMHC catalog products, visit the specific product page to view the lead time. For custom prMHC orders, the lead time is 6 to 8 weeks. 

Our Products

KACTUS provides catalog and customized prMHC monomers, biotinylated monomers, and fluorescent tetramers. 

We analyze prMHC products for molecular weight (Tris-Bis PAGE), purity (Tris-Bis PAGE & SEC-HPLC), endotoxin, and concentration. Our prMHC products have > 95% purity and < 1 EU/µg.

Yes, KACTUS provides custom prMHC-I and prMHC-II for all available MHC alleles. Contact us at to request a custom MHC.

prMHCs can be stored for at least 12 months at -80°C. 

About Peptide-Ready MHCs

Peptide-ready MHCs (prMHC) is an MHC that doesn’t contain any pre-loaded peptide and can be loaded with custom peptides for TCR binding and cell staining. 

A prMHC monomer consists of an α-chain and β-2 microglobulin. It is a single subunit of prMHC tetramer.

It is a prMHC monomer with biotin at the C-terminal Avi tag.

A fluorescent prMHC tetramer is a complex of four prMHC monomers with fluorophores conjugated to each monomer subunit of the prMHC complex.

Expression of prMHCs

Yes, KACTUS prMHCs are a propriety design based on our SAMS™ Protein Engineering Platform.

Yes, prMHC are a single-chain design of α-chain and β-2 microglobulin developed by our protein engineering team.

Yes, prMHCs are purified from HEK293 cells.

prMHCs are affinity-purified via His tag at the C-terminus with additional size exclusion chromatography steps.

No, prMHC tetramerize in vivo during expression in HEK293, a KACTUS propriety design.

Fluorescent Labeling

We currently offer APC-equivalent, FITC-equivalent and PE conjugation for prMHC tetramers.

APC-equivalent is a 90 kDa protein, with excitation peak at 609 nm and emission peak at 643 nm.

No, APC-equivalent is an in vivo label, part of KACTUS proprietary single chain design for fluorescent prMHC tetramer. 

Protocols & Applications

Yes, contact for a protocol.

Yes, KACTUS prMHCs can be used for peptide screening. 

Yes, contact for a protocol.

Still have questions? Email to get in touch.


[1] Moritz A, Anjanappa R, Wagner C, Bunk S, Hofmann M, Pszolla G, Saikia A, Garcia-Alai M, Meijers R, Rammensee HG, Springer S, Maurer D. High-throughput peptide-MHC complex generation and kinetic screenings of TCRs with peptide-receptive HLA-A*02:01 molecules. Sci Immunol. 2019 Jul 19;4(37):eaav0860.

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