Protein Foundry’s recombinant chemokines are expressed in E. coli bacterial cultures using plasmid based vectors engineered to yield chemokines with native N-termini. A series of ion exchange and reversed phase high-performance liquid chromatography (RP-HPLC) steps are utilized to ensure that our recombinant chemokines maintain the highest level of purity and the native disulfide bond pairings found in chemokines extracted from their native sources. Purified products are lyophilized with no additives or preservatives added and subject to a rigorous set of quality control standards that include:
- Purity and content * – Verified by SDS PAGE analysis and RP-HPLC.
- Authenticity– Verified by mass spectrometry to ensure the correct molecular weight.
- Structural integrity – Verified by 1 and 2-dimensional NMR spectroscopy to ensure that our proteins are properly folded.
- Biological activity – Confirmed using in vitro calcium flux and/or chemotaxis assays where available.
- Endotoxin contamination – Tested by the (LAL Limulus Amebocyte Lysate) method to ensure the lowest possible endotoxin levels.
- Sterility – All products are filtered through a 0.1 micron filter.
The rigorous purification protocols and quality control standards employed at Protein Foundry ensure lot-to-lot consistency required for any successful research campaign.
* All recombinant proteins produced and sold by Protein Foundry, LLC are <0.01 EU per 1 μg of the protein as determined by the LAL method.