What is an elisa? I had an ELISA test, but I don't understand what it is.

Radiation-free test. Elisa is a test that detects a foreign substance (antigen) or an antibody in blood. Elisa uses an enzyme bound to a 2nd antibody. In the final step the enzyme converts indicator material to a different color. The amount of color detected corresponds to the amount of antigen or antibody present. Elisa gives the same answer as rast without using radioactive radioisotopes.
ELISA. An eliza is a blood test in which serum antibody from the patient is incubated with the target antigen bound to a plastic surface. Non-binding antibody is washed away and the remaining antibody is detected by a second indicator antibody that has an enzyme attached to it. This second antibody can specifically detect protective antibody (igg, IgM or iga) or some can bind to allergic antibody ige.