Protein A Ligands

Repligen has been the world's leading producer of recombinant Protein A for over 20 years. Over half the world's commercial monoclonal antibodies are purified on recombinant Protein A manufactured by Repligen.

Repligen supplies Protein A from milligram to multi-kilogram quantities. Whether it is for small scale laboratory purification and immunoprecipitation or large scale for OEM partners who use it as a critical raw material in the manufacuring of their own proprietary products our recombinant Protein A meets the strictest demands of our customers. Our ISO certified manufacturing ensures the highest quality in terms of purity and performance as well as supply chain security. Repligen's Protein A is a critical component of proprietary products that are used every day in biopharmaceutical purification processes supporting the safe and effective production of important breakthrough drugs for diseases such as rheumatoid arthritis, breast cancer and multiple sclerosis.

Recombinant Protein A, is expressed in E. coli as opposed to the native protein extracted from Staphylococcus aureus. Repligen customers can expect economic and supply chain benefits that are derived directly from our expertise in the optimization of E. coli fermentation and purification processes which has resulted in very high expression levels [titers] and high yielding downstream processes.

rSPA - Repligen's native recombinant Staphylococcal Protein A represents the most advanced non mutant Protein A ligand. The combination of comparable performance and purity to native Protein A (see table) and outstanding economics and supply chain security, makes rSPA the automatic first choice for all new Protein A ligand applications.

Ligand - Characteristics

rSPA - contains the same amino acid sequence and molecular mass as the native Protein A sourced from S. aureus. rSPA is manufactured with animal-free materials. Native Protein A is used in multiple commercial products with a long regulatory history. rSPA is an ideal substitute or replacement to native Protein A. This is the most modern ligand and will in many cases demonstrate improved target protein binding. It should be considered the ligand of first choice for all new processes not only for its potential performance improvements but also for supply chain security and overall value proposition.

rSPA - Ordering and Pricing Information

rSPA Products

NOTE: Repligen is pleased to provide standard list pricing for these smaller research quantities of Protein A. If larger quantities are required please contact Repligen directly for information on our volume based supply agreement programs.

Repligen's legacy recombinant Protein A products rPA50 and srPA50 are mainly restricted to already validated processes. These ligands are still available through custom order.

  • rPA50 - Contains materials of animal origin. The fermentation media contains the following animal derived components; casin, calf rennet and porcine pancreatic enzymes. However, Repligen does provide "Material of Animal Origin" certification.
  • srPA50 - Like rPA50 this "recombinant Protein A" affinity ligand is produced in Escherichia coli. This ligand is identical to Repligen's "original" recombinant construct. It is an exact sequence match to rPA50 having all five IgG binding domains (E, D, A, B, C). The notation "s" in front of the rPA50, indentifies that the protein srPA50 is manufactured with soy based, animal free fermentation media.

Please call Repligen BioProcessing for information and availability of these products.

Protein A (native)

Purification ligands from a leading manufacturer used to isolate IgG from crude protein mixtures.

Protein A is a purification ligand that binds proteins from many mammalian species, in particular it binds with high affinity to the Fc region of IgG's. When immobilized on a matrix, e.g; Sepharose, Protein A can be used to isolate IgG from crude protein mixtures.

Repligen has been in the business of producing n Staph Protein A for purification applications for over 16 years. At the recently expanded facility in Lund, Sweden, kilogram quantities of high quality product is manufactured every year.

Regulatory-compliant to meet the strictest requirements
Protein A meets the strictest demands of our drug manufacturers in terms of purity, reproducibility, binding capacity, specificity and other key measures critical to the quality of downstream processes, allowing the production of important and innovative biopharmaceutical drugs.

Product specifications and features - Protein A

  • Reliable performance: Fc specific binding to IgG
  • Guaranteed purity: > 95% purity by SEC
  • Activity: > 95% IgG-binding activity
  • NOT purified by hIgG affinity
  • Produced according to cGMP.