Step 1 – coating
ELISA begins with a coating step where the ELISA plate (typically either a 96- or 384-well plate) is treated with a coating solution of either antigen or antibody. The antigen or antibody is absorbed to the well-surface of the ELISA plate, creating the first layer. Then the coating buffer is removed, followed by a series of washes to remove unbound antigen or antibody.
Washes are repeated between each ELISA step to remove unbound materials. Furthermore, it is essential that excess liquid is removed to avoid dilution of the solution added in the next assay step. We provide specialised microplate washers to ensure uniformity.
Step 2 - blocking
In the second step, all free binding sites are blocked using a buffer containing unrelated proteins. This step is important to eliminate a potential source of false positive results. Blocking buffer removal is again followed by a series of washing steps.