Coating: The antigen or antibody of interest is bound to a solid surface, usually a microplate. Blocking: Non-specific binding sites are blocked to prevent false positives. Detection: A specific antibody linked to an enzyme is added. If the antigen is present, the enzyme-linked antibody will bind to it. Substrate Addition: A substrate that the enzyme can convert to a detectable signal (often color change) is added. Measurement: The intensity of the signal is measured, usually using a spectrophotometer, to determine the presence and quantity of the antigen or antibody.
