The SDF-1? ELISA (Enzyme-Linked Immunosorbent Assay) kit is an in vitro enzyme-linked immunosorbent assay for the quantitative measurement of Human SDF-1? in plasma (serum samples are not recommended for use in this assay (Human SDF-1? concentration is pretty low in normal plasma, it may not be detected in this assay), cell culture supernatants and urine.