Human SDF1 protein, His tag (active)

SDF1 (stromal cell-derived factor 1), also known as C-X-C motif chemokine 12, is a chemokine protein that has chemotaxis active on T-lymphocytes and monocytes. It is thought that SDF1 stimulates migration of monocytes and T-lymphocytes through its receptors, CXCR4 and ACKR3; thus, chemotaxis assay used 24-well microchemotaxis system was undertaken to detect the chemotactic effect of SDF1 on the human monocytic cell line THP-1. Briefly, THP-1 cells were seeded into the upper chambers (100 μl cell suspension, 1x10⁶ cells/ml in RPMI-1640 with 0. 5% FBS) and SDF1 (10 ng/ml, 30 ng/ml and 60 ng/ml diluted separately in serum free RPMI-1640) was added in lower chamber with a polycarbonate filter (8μm pore size) used to separate the two compartments. After incubation at 37ºC with 5% CO₂ for 3h, the filter was removed, then cells in low chamber were observed by inverted microscope at low magnification (×100) and the number of migrated cells were counted at high magnification (×400) randomly (five fields for each filter). The migrated THP-1 cells in low chamber at low magnification (×100) randomly, and the migrated cells were counted at high magnification (×400). SDF1 is able to induce migration of THP-1 cells, and the optimum chemotaxis of SDF1 occurs at 10-60 ng/ml.