- Sandwich ELISA Protocol (Chemicon)
Sandwich ELISAis used to determine the antigen concentration in unknown samples. This protocol describes both the principals and prcedures of sandwich ELISA, it also lists troubleshootings.
Added: Mon Apr 19 2004, Hits: 18205, Reviews: 0
Dot-ELISA (Enzyme Linked Immunosorbent Assay) is an extensively used immunological tool in research as well as analytical/diagnostic laboratories. In sandwich Dot-ELISA, the antigen is sandwiched directly between two antibodies which react with two different epitopes on the same antigen. Here one of the antibodies is immobilized onto a solid support and the second antibody is linked to an enzyme. Antigen in the test sample first reacts with the immobilized antibody and then with the second enzyme-linked antibody. The amount of enzyme linked antibody bound is assayed by incubating the strip with an appropriate chromogenic substrate, which is converted to a coloured, insoluble product. The latter precipitates onto the strip in the area of enzyme activity, hence the name Dot-ELISA. The enzyme activity is indicated by intensity of the spot, which is directly proportional to the antigen concentration.
Added: Fri Apr 19 2013, Hits: 564, Reviews: 0
(Kitto Lab, The University of Texas at Austin)
The sandwich ELISA measures the amount of antigen between two layers of antibodies. The antigens to be measured must contain at least two antigenic sites, capable of binding to antibody, since at least two antibodies act in the sandwich. So sandwich assays are restricted to the quantitation of multivalent antigens such as proteins or polysaccharides. Sandwich ELISAs for quantitation of antigens are especially valuable when the concentration of antigens is low and/or they are contained in high concentrations of contaminating protein.
Added: Tue Oct 08 2002, Hits: 12150, Reviews: 0
Sandwich ELISA For Detecting Secreted ICAM-1
(Springer Lab, Harvard University)
Added: Wed Aug 14 2002, Hits: 2733, Reviews: 0