Granulocyte Macrophage Colony Stimulating Factor (GM-CSF), human recombinant (rHuGM-CSF)

Recombinant Human GM-CSF produced in insect cells is a single, glycosylated, polypeptide chain containing 127 amino acids and having a molecular mass of 14477 Dalton. Recombinant Human GM-CSF is fused to a C-terminal His -tag (6x His) and purified by proprietary chromatographic techniques. , Amino acid sequence:, The sequence of the first five N-terminal amino acids was determined and was found to be Ala-Pro-Ala-Arg-Ser. N-terminal methionine has been completely removed enzymatically. Biological Activity: Recombinant GM-CSF is fully biologically active when compared to standard. The ED50 as determined by the dose-dependent stimulation of the proliferation of human TF-1 cells (human erythroleukemic indicator cell line) is < 0.1ng/ml, corresponding to a Specific Activity of 1x10e7 IU/mg. Protein content: Protein quantitation was carried out by two independent methods: , 1. UV spectroscopy at 280nm using the absorbency value of 0.963 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 GM-CSF as a Reference Standard. Storage and Stability: Lyophilized powder may be stored at 4°C for short-term only. Reconstitute to nominal volume by adding sterile dH2O or buffer of choice and store at -20°C. Reconstituted product is stable for 12 months at -20°C. 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.