||Recombinant Human IFN-alpha 2a produced in E. coli is a single, non-glycosylated, polypeptide chain containing 165 amino acids and having a molecular mass of 19241 Dalton.
||At least 23 different variants of IFN-alpha are known. The individual proteins have molecular masses between 19-26 kDa and consist of proteins with lengths of 156-166 and 172 amino acids. All IFN-alpha subtypes possess a common conserved sequence region between amino acid positions 115-151 while the amino-terminal ends are variable. Many IFN-alpha subtypes differ in their sequences at only one or two positions. Naturally occurring variants also include proteins truncated by 10 amino acids at the carboxy-terminal end.
||>95% as determined by SDS-PAGE and SEC-HPLC.
||rHuIFNa2a is lyophilized from (1mg/ml) solution containing 7.21 sodium chloride and 0.77mg ammonium acetate.
||The specific activity as determined in a viral resistance assay using VSV-WISH cells was found to be greater than 1.0 x 108IU/ mg.
||Less than 0.3ng/µg (0.3IEU/µg) determined by LAL test.
||It is recommended to reconstitute the lyophilized rHuIFNa2a in sterile 18MΩ-cm H2O not less than 100µg/ml, which can then be further diluted to other aqueous solutions.
||Lyophilized rHuIFN-alpha 2a although stable at room temperature for 3 weeks, should be stored desiccated below -18°C. Upon reconstitution rHuIFNα2a should be stored at 4°C between 2-7 days and for future use below -18°C. For long-term storage it is recommended to add a carrier protein (0.1% HSA or BSA). Aliquot to avoid repeated freeze-thaw cycles.