Companies that provide protein expression and purification services enter the service at a different starting point. Some have peptide synthesis expertise and think of proteins as long peptides. Others have gene synthesis expertise and extend their services into protein expression as an off-shoot of their gene synthesis services. Some make antibodies and make proteins as antigens, usually without particular care for proteins folding state or functional integrity. Affina Biotechnologies advantage is based on our expertise in measuring activity and binding ability coupled to years of experience in protein expression and purification. As a result of our experience in working with functional proteins the proteins we produce are tested at every stage of purification and are active as the final products. We can even test proteins functionality as early as during expression analysis ensuring that the constructs that are being expressed result in useful reagents. We are not a company that should be selected for the lowest cost production of a polypeptide that is characterized as a band on SDS-PAGE. We are the company to choose if you want functional, highly purified proteins that are necessary for screens, detailed mechanistic and structural studies.
Expression Analysis and Optimization
We specialize in protein expression in bacterial and baculovirus/insect cells expression systems. Expression can be optimized in up to 48 different conditions simultaneously to select the highest level of functional protein expression with different expression constructs, promoters, temperature, media components and time of expression. Expression levels are analyzed by SDS-PAGE, Western blot, ELISA, activity assay or surface plasmon resonance as needed.
Proteins can be purified as soluble proteins with and without tags or as inclusion bodies which can be refolded as required. We have worked out a number of refolding methods that allow us to isolate refolded proteins that are as functional as those produced in the soluble fractions. We can also measure endotoxin and remove it to the specification provided by the client.