Haematoxylin counterstaining of immunofluorescence preparations.

Abstract

A standardized suitable nuclear counterstaining procedure was sought which could preserve IF [immunofluorescence] staining on tissue sections. Immunostained cryostat sections retained their fluorescence activity for a long time and could be successfully counterstained with Gill''s hematoxylin when previously mounted in glycerol-formalin (9:1). Under these conditions both IF staining and nuclear hematoxylin counterstaining could be revealed on the same cells by just changing the illumination system. Hematoxylin staining completely removed IF when formalin was omitted in the mounting medium. Post-fixation is essential for an adequate preservation of IF staining together with a proper nuclear counterstaining after hematoxylin. Several fixation procedures were investigated on immunostained preparations in order to find an optimal staining sequence.