Recombinant Human SDF-1 alpha/CXCL12

This lyophilized preparation is stable at 2-8C, but should be kept desiccated at -20C for long term storage. Upon reconstitution, the preparation is stable for up to one week at 2-8C. For maximal stability, apportion the reconstituted preparation into working aliquots and store at -20C to -80C. Avoid repeated freeze/thaw cycles.

SDF-1alpha and SDF-1beta, members of the chemokine alpha subfamily that lack the ELR domain, were initially identified using the signal sequence trap cloning strategy from a mouse bone-marrow stromal cell line. These proteins were subsequently also cloned from a human stromal cell line as cytokines that supported the proliferation of a stromal cell-dependent pre-B-cell line. SDF-1alpha and SDF-1beta cDNAs encode precursor proteins of 89 and 93 amino acid residues, respectively. Both SDF-1alpha and SDF-1beta are encoded by a single gene and arise by alternative splicing. The two proteins are identical except for the four amino acid residues that are present in the carboxy-terminus of SDF-1beta and absent from SDF-1alpha. SDF-1/PBSF is highly conserved between species, with only one amino acid substitution between the mature human and mouse proteins. SDF-1/PBSF acts via the chemokine receptor CXCR4 and has been shown to be a chemoattractant for T-lymphocytes, monocytes, pro- and pre- B cells, but not neutrophils. Recombinant Human SDF-1 alpha is a single, non-glycosylated polypeptide chain consisting of 68 amino acids.

Centrifuge vial prior to opening. Add sterile distilled water or aqueous buffer to a concentration of 0.1-1.0 mg/ml. Further dilutions should be made in appropriate buffered solutions.

Fully biologically active when compared to standard. The ED50 determined by a chemotaxis bioassay using human peripheral blood T-lymphocytes is less than 9 ng/ml.