Multicolor counterstaining for immunohistochemistry – a modified Movat's pentachrome

The application of "histochemical" staining procedures has been substantially replaced by immunostaining of specific molecular tissue components. The limited range of colors resulting from routine immunohistochemistry, however, can limit assessment of the general microscopic tissue organization. Consequently we have adapted a polychromatic histochemical counterstaining procedure based on Movat's pentachrome staining sequence for use with immunohistochemical procedures. The value of Movat's original method when applied as an immunohistochemical counterstain is limited by its use of iron hematoxylin and by fact that the resulting color combination is difficult to distinguish from the colors of routine immunohistochemical staining. Our variant pentachrome stains the same tissue components as Movat's stain; however, owing to a modification of the acid fuchsin staining step, it provides a strong color contrast with the reaction product resulting from immunostaining using diaminobenzidine as the chromogen. Multicolor counterstaining for immunohistochemistry offers a new approach to tissue analysis, especially when stromal-epithelial relations of normal and neoplastic tissues are considered.