S-adenosylmethionine (SAM) is a substrate for methyl transfers to various biomolecules that yields S-adenosylhomocysteine (SAH). SAH is then hydrolyzed to homocysteine and adenosine, which is converted to methionine, and ultimately back to SAM. SAH can act as a methylation inhibitor, therefore the SAM/SAH ratio, or methylation potential, is important for maintaining proper methylation in the cell.
Our S-adenosylmethionine (SAM) ELISA is designed for detection and quantitation of SAM in plasma, serum, lysates, or biological fluid samples. This assay is a competitive ELISA where samples and an anti-SAM antibody are added to a plate coated with a SAM conjugate. The sample and conjugate compete for antibody binding, which generates a reverse curve. Samples with high SAM levels will bind the majority of the antibody, which gets washed away and results in a low OD, while samples with low SAM levels will leave more antibody available to bind to the conjugate, producing a high signal.