ELISA stands for enzyme linked immunosorbent assay. Antibodies are used to detect the amount of protein in a sample. It is extremely sensitive and can detect small amounts of the protein.The antigen is placed on a slide. Excess antigen is washed off.The antibody for the antigen to be tested is added to the slide. The antibody binds to the antigen and the excess is washed off.A second antibody that binds to the first antibody is added. This second antibody is attached to an enzyme which acts on a colourless substrate.The substrate is added and the second antibody turns it into a coloured product.
The intensity of colour is measured and used to calculate the amount of antigen present.The ELISA test is a very sensitive test and can be used to detect antigens of pathogens such as HIV, TB and hepatitis.
The intensity of colour is measured and used to calculate the amount of antigen present.The ELISA test is a very sensitive test and can be used to detect antigens of pathogens such as HIV, TB and hepatitis.