The Human Latent Transforming Growth Factor-beta 1 (TGF-β1) Kit is designed for the quantitative detection and measurement of latent human TGF-β1 in biological fluids such as plasma and cell culture supernatants. TGF-β1 is produced primarily by platelets and bone, and in smaller amounts by most nucleated cells and tumors. TGF-β1 stimulates cells of mesenchymal origin, but inhibits cells of epithelial or neuroectodermal origin. TGF-β1 associates with Latency Associated Protein (LAP) to form a latent complex. This kit detects the LAP entity of the complex.

The assay is based on the sandwich ELISA method, in which samples are added to ELISA strip plates pre-coated with capture antibodies specific for the cytokine. The captured cytokine is detected by addition of a biotinylated detection antibody, followed by streptavidin-horseradish peroxidase, which binds the biotinylated antibody. Addition of the chromogenic enzyme substrate 3,3’,5,5’ tetramethylbenzidine (TMB) results in a colored product with an intensity directly proportional to the concentration of cytokine in the sample. The concentration of the cytokine is determined by comparison to a serial dilution of the cytokine standard analyzed in parallel.