Recombinant Human SCF is a single, non-glycosylated polypeptide chain containing 165 amino acids and having a molecular mass of 18409 Dalton.Sequence:First five N-terminal amino acids: Met-Glu-Gly-Ile-Cys.Biological Activity:Fully biologically active when compared to standard. The ED50 as determined by the dose-dependent stimulation of Human TF-1 cells is less then 2ng/ml, corresponding to a Specific Activity of 10e5 IU/mg.Protein Content:Protein quantitation was carried out by two independent methods:1. UV spectroscopy at 280 nm using the absorbency value of 0.52 as the extinction coefficient for a 0.1% (1mg/ml) solution. This value is calculated by the PC GENE computer analysis program of protein sequences (IntelliGenetics). 2. Analysis by RP-HPLC, using a standard solution of SCF as a Reference Standard.Storage and Stability:Lyophilized powder may be stored at -20°C..Reconstitute with sterile ddH2O, 0.1% HSA or BSA. Reconstituted product is stable for 6 months at -20°C. For maximum recovery of product, centrifuge the original vial prior to removing the cap. Further dilutions can be made in assay buffer.