MHC Complexes

100+ Catalog Items
Custom Production

VLP Antigens

Secretory Proteins


Endonuclease for DNA/RNA


Quantification of AAV capsids
Specific, sensitive, reproducible

Designed to provide high processivity and high fidelity during in vitro DNA amplification reactions.

Phi29 DNA Polymerase: isothermal DNA amplification for rolling circle amplification, multiple displacement amplification, and whole genome amplification

TelN Protelomerase: dsDNA cleavage leaving covalently closed ends

Exonuclease III: removal of nucleotides from linear or nicked dsDNA

→ Full range of enzymes for template preparation, transcription, & modification.

→ GMP-grade & GMP-ready.

→ Registered with FDA Drug Master Files (DMF)

T7 RNA Polymerase, BsaI, T4 RNA Ligase I

Custom Production

→ Scientific support for structure optimization specific to your application
→ Bulk supply for research, process development, quality testing, etc.
→ GMP-grade production for clinical manufacturing
→ Equipment certification, batch records, etc. for regulatory filing


We specialize in providing high-quality recombinant proteins and enzymes for antibody drug discovery, immunotherapy, gene therapy, and mRNA therapeutics.

Our 2400+ catalog products include VLP-Displayed Antigens, MHC Complexes, Laminin 521, CD3 Proteins, and GMP-Grade CRISPR Cas9. We also offer custom recombinant protein production using our proprietary protein engineering platform, SAMS™.

Facilities & equipment

→ R&D production headquarters of over 50,000 square feet
→ GMP-production facility of over 100,000 square feet
→ Scientific team of 200 researchers and production engineers

SAMS™ Technology Platform

→ Structure Aided Design and Multiplex Screening (SAMS) 
→ Optimizes protein configuration and expression conditions 
→ Bioactive proteins in multiple cell lines.

Learn More

Quality Systems

→ High-purity and bioactive proteins
→ Extensive quality control testing, including activity testing
→ Optional GMP-grade material for commercial manufacturing

Learn More

What's new at KACTUS

ASGCT 2023

ASGCT 2023

  Find KACTUS at the ASGCT Annual Meeting in sunny L.A. May 16-20th! Come by our booth to pick up some swag including t-shirts, sharpies, sticker...

Read more