A rapid method for monitoring DNA labelling reactions with haptens

A rapid and simple method for evaluating the efficiency of DNA labelling reactions with haptens is described. The method, called the Flow-Through Hapten-DNA Assay (FT-HDA), relies on binding of anti-hapten antibodies/alkaline phosphatase conjugates to hapten-DNA, immobilized on disposable capillary absorbent filters, and visual detection of blue-grey coloured spots appearing on the filter after chromogenic reaction with enzyme substrates. FT-HDA of hapten-DNA is markedly faster and simpler than conventional diffusion assays on membranes.