This short article aims to identify and explain the common ELISA keywords you are likely to encounter when reading an ELISA protocol.
- Solid Phase– Normally a microtiter plate well. Specially prepared ELISA plates are available commercially and be found on elisagenie.com
- Adsorption– This is the process of adding an antigen or antibody so that it attaches passively to the solid phase on incubation.
- Washing– Is the flooding of the wells with buffered solution. This remove unbound reagents.
- Antigen– A substance usually a protein which induces an immune response in the form of antibodies. The antibody produced is specific to the antigen it encounters.
- Antibody– Produced in response in to antigenic stimuli. Mainly protein.
- Enzyme– A substance which acts as a catalyst to promote a specific reaction. Enzymes act on specific substrates.
- Enzyme conjugate– A enzyme which is attached to a protein usually an antibody such as a mouse anti-rabbit linked to HRP (horseradish peroxidase).
- Substrate– A compound which reacts specifically with an enzyme. This reaction in ELISA produces a signal detectable directly by colour change.
- Chromophore– A chemical that alters colour as a result of the enzyme interaction with substrate.
- Stop solution– Stops the action of an enzyme on a substrate, stopping any further colour change.
- Reading– Measurement of color produced in the ELISA. This is quantified using a spectrophotometer reading at specific wavelengths for the specific colours obtained with particular enzyme/chromophore systems.