ELISAmenetelmiä

ELISAmenetelmiä, or Enzyme-Linked Immunosorbent Assays, are a group of analytical techniques commonly used in biology and medicine. They are designed to detect and quantify substances like antibodies, antigens, proteins, and peptides in a sample. The core principle of ELISA relies on the specific binding of an antibody to its target antigen.

There are several variations of the ELISA technique, each suited for different applications. The direct ELISA is the simplest, where the antigen is directly immobilized on a solid surface and then detected by a labeled antibody. The indirect ELISA involves immobilizing the antigen and then adding a primary antibody, followed by a labeled secondary antibody that binds to the primary antibody. The sandwich ELISA is particularly useful for detecting antigens; here, a capture antibody is immobilized, followed by the antigen, and then a detection antibody. Finally, the competitive ELISA measures the concentration of an antigen by observing the competition between a labeled antigen and the unlabeled antigen in the sample for binding to a limited amount of antibody.

All ELISA methods typically involve a series of washing steps to remove unbound substances and a final step where a substrate is added to a bound enzyme. This enzyme catalyzes a reaction that produces a measurable signal, often a color change, which is then quantified using a spectrophotometer. The intensity of the signal is directly proportional to the amount of the target substance present in the sample. ELISA is widely employed for diagnostic testing, research, and quality control.