An enzyme-linked immunosorbent assay, also known as an ELISA kit, is a test that uses antibodies/ antigens and color change to identify a substance. The ELISA has been used as a diagnostic tool in medicine and plant pathology, as well as a quality-control check in various industries. ELISA kits are ideal for the quantification of target antibodies/ antigens in tissue extracts, serum and cell culture. Elabscience offers a great variety of professional ELISA kits for your biological research which have been exhaustively recognised for its quality-reliable and time-saving. Elabscience ELISA kits can be classfied into several categories by test method, such as colorimetric (including Sandwich-ELISA and Competitive-ELISA), and fluorescence.
Sandwich ELISA is a widely used method of quantifying target molecule concentration in a certain sample type with high precision and sensitivity. It is named sandwich ELISA because the target antigen/antibody is sandwiched by a captured antigen/antibody bound to the well and the detecting antigen/antibody. The concentration can be calculated by measuring the color change caused by the enzymatic reactions with a spectrometer.
Competitive ELISA is a commonly used and effective method for detection of small molecule antigen. In a competitive ELISA, a labelled competitor molecule is incubated with the detection antibody and sample. As the ratio of sample molecule to label competitor increases, the signal is reduced because less competitor is able to bind to the detection antibody. The signal on a competitive ELISA actually decreases, as the concentration of the target molecule in your sample increases.