Enzyme Linked Immuno Sorbent Assay (ELISA) is a widely used method for both research and diagnostic purposes. It is an assay where the reaction between the antigen and its antibody takes place linked to a solid phase. For visualization of the antigen-antibody reaction an enzyme and the related substrate offer a coloured reaction which can be measured spectrophotometrically. Different substrates are available to the enzyme conjugates used in ELISA. TMB (3, 3’, 5, 5’-tetramethylbenzidine) is the most commonly used substrate for the enzyme horseradish peroxidase (HRP) and the combination is one of the most acknowledged ELISA detection systems. ’’Mono-component TMB systems combine TMB, substrate buffer and hydrogen peroxide for safe, ready-to-use, one step products for direct use in your preferred ELISA format.
TMB yields a soluble blue end product read at 655 nm. The reaction may be stopped by 0.2 M sulphuric acid which offers a yellow end product read at 450 nm. Ready-to-use TMB substrates are available in different activity levels to match individual requirements. All types of ELISA TMB products are available also as prestained, colour coded products for maximum convenience.
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