Recombinant Human SCF produced in insect cells is a single, glycosylated polypeptide chain containing 165aa and having a molecular mass of 118.41kD containing a C-terminal His-tag (6x His).Biological Activity: The ED50 as determined by the dose-dependent stimulation of Human TF-1 cells is typically 2-5ng/ml. 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. Stable for 12 months at -20°C. Reconstitute with sterile ddH2O ,0.1% HSA or BSA. Aliquot and store at -20°C. Stable for 6 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.