A SIMPLE EPITOPE RETRIEVAL METHOD WITHOUT THE USE OF MICROWAVE-OVEN OR ENZYME DIGESTION

A simple epitope retrieval method has been developed in our research l aboratory for immunostaining of formalin-fixed, paraffin-embedded tiss ues. This method is easy to use, as it only involves an overnight incu bation of deparaffinized sections in a regular oven at 70 to 80 degree s C with 10mM citrate buffer (pH 6.0) prior to immunostaining. With th is approach, a variety of nuclear and cytoplasmic antigens known to re quire microwave irradiation or enzymatic digestion for their optimal d etection could be clearly demonstrated with excellent preservation of morphology, intense reactivities, and clean backgrounds. Also, optimal immunostaining for each of the 15 antibodies tested was observed even when sections from 15 different cases were incubated together with 10 mM citrate buffer, then immunostained in an identical manner with manu facturers' recommended antibody concentrations. The drawback of our me thod is that it takes longer to yield results.