A simple and reliable immunohistochemical method for colocalization of 2 antigens in the same cells of paraffin-embedded tissues.

Immunohistochemistry (IHC) lacks an efficient technique for colocalizing multiple antigens in the same cells of a single tissue section. The development of a methodology which combines the advantage of low cost, high sensitivity, and specificity would benefit clinical diagnosis and general research. On the basis of a newly published method of visualizing 2 antigens on a single paraffin-embedded tissue section, we have further developed a novel sequential technique for colocalizing 2 different antigens in a same cell in a paraffin-embedded tissue section. In this technique, we combined the microwave heating technique (MVT) with normal IHC methods to sequentially double stain a paraffin section; and colocalize 2 antigens in a single cell through result comparison stored in a digital management system. This MVT colocalization method has a higher degree of sensitivity and specificity comparable with conventional staining of both immunofluorescence and IHC systems. The primary advantage of this method is that it is inexpensive and convenient; the antibody(s) used in this method can be generated from the same or different species; it allows colocalization or comparison of different results of cell morphology for any single cell of the section on 2 images, avoids uncertainty when overlapping 2 antigens on a single image.