What follows the addition of the peroxidase linked drug conjugate in a classical ELISA test?

In a classical ELISA test, after adding the peroxidase-linked drug conjugate, the next step is to ensure that any unbound conjugate is removed from the wells of the plate. This is achieved through plate washing. Washing helps to eliminate excess conjugate that has not bound to the target, thereby reducing background noise and enhancing the specificity of the assay.

Following the addition of the peroxidase-linked conjugate, a binding event occurs—if the target analyte is present, the conjugate binds to it. To ensure that only specifically bound conjugate is retained, the plate is then washed, which is crucial for achieving accurate and reliable results in the assay.

The next step after washing would typically involve a colorimetric evaluation, as it is during that phase that the actual detection of the bound conjugate occurs. However, washing must come first to prepare the plate for this evaluation. Thus, the sequence of steps in performing an ELISA methodology highlights the significance of proper washing following the addition of the conjugate.