Human Smad4/MADH4 ELISA Kit

Assay Genie's sandwich ELISA kit is designed for the quantitative measurement of SMAD4 (also known as MADH4) in human samples. The assay uses a double-antibody sandwich format with colorimetric detection, achieving a sensitivity of 0.188 ng/mL across a working range of 0.313–20 ng/mL.

Compatible sample types include serum, plasma, cell culture supernatant, cell or tissue lysate, and other liquid samples, with storage at 2–8°C for 12 months. SMAD4 is a key mediator of the TGF-beta signaling pathway, regulating cell growth, differentiation, and apoptosis, and its dysregulation has been implicated in cancer, fibrosis, and developmental disorders. The associated Uniprot entry is Q13485.

Reported linearity for serum spans 82–100% at 1:2, 81–100% at 1:4, and 90–98% at 1:8 dilution (n=5); EDTA plasma spans 82–98%, 82–92%, and 85–105%; heparin plasma spans 85–100%, 87–101%, and 82–99%. Average recovery is 95% for serum (range 86–103%), 93% for EDTA plasma (range 85–100%), and 90% for heparin plasma (range 85–105%). The assay protocol involves a 90-minute primary incubation at 37°C, a 60-minute biotin-labeled detection antibody step, a 30-minute HRP-streptavidin incubation, 10–20 minutes of TMB substrate development in the dark, and absorbance reading at 450 nm after addition of stop solution.