S-Adenosyl Methionine
S-adenosyl methionine (also referred to as SAM, SAMe or AdoMet) plays a crucial role in the biological process of methylation in all types of organisms. In the methylation cycle, SAM serves as the donor of the methyl group used in the covalent modification of DNA and proteins. Variability in SAM levels have been linked to the processes of aging, numerous neurological and psychiatric disorders including Alzheimer’s disease, depression, HIV-related neurological dysfunction/dementia, multiple sclerosis, Parkinson’s disease, spinal cord degeneration, epilepsy, fibromyalgia, migraine headaches, and also chronic liver dysfunction, arteriosclerosis and cancer. Currently, SAM is quantified using the high pressure liquid chromatography (HPLC) method. HPLC is time consuming, costly and, due to the large amount of organic solvent required, not environmentally friendly.
Bridge-It® S-Adenosyl Methionine Fluorescence (SAM) Assay
Mediomics Bridge-It® S-adenosyl methionine (SAM) fluorescence assay method is based on a combination of well-established fluorescence measurement techniques and our patented new assay platform design that utilizes DNA-binding proteins as biosensors for their respective small molecule co-regulators (ligands). The affinity of the DNA sequence-specific MetJ protein for its unique DNA-binding site is greatly increased in the presence of its ligand, S-adenosyl methionine. For this assay, the MetJ consensus sequence was split into two DNA “half-sites”. One half fragment was labeled with fluorescein and the other half fragment was labeled with Oyster® 645 fluorophore3,4. The relative amount of SAM present in a test sample will influence the amount of DNA-MetJ protein complex formation in the assay. When this complex forms, it brings the fluorescence labeled-DNA half-sites into close proximity and causes a measurable change (increase) in fluorescence signal emission that can be readily measured using a microplate reader (wavelength settings: absorption 485 nm; emission 665 nm). SAM concentrations in test samples are then determined using a SAM standard curve. The Bridge-It® SAM fluorescence assay method exhibits highly desirable performance characteristics including a high (>5:1) signal to background (S/B) ratio, a broad linear dynamic range (0.5 µM – 20 µM), and, a detection sensitivity of 0.5 µM. This detection level (0.5 µM) is useful for quantifying SAM in most test samples of interest including biological fluids, cell culture and fermentation medium, and extracts of tissues and cells.
More information at : http://mediomics.com/product/bridge-s-adenosyl-methionine-sam-fluorescence-assay-kit-96-well-format/
*384 well format also available