Improved method to calculate the antibody avidity index.

The methods currently used to determine the immunoglobulin avidity index (AI) require the choice of a reference point in the ELISA titration curve. Since both curves, with and without denaturating reagents, seldom run in parallel, the AI value becomes highly dependent on this reference. The new method for AI calculation presented here takes into account the whole data of the ELISA titration curve in which the final numerical AI is the average of each point.