Detection of different functional states of the cellular nucleus with a new trichrome staining technique

The new trichrome stain ASTRIN, prepared from alcian blue, safranine, thionine, and resorcin, stains the cell nuclei red or blue, depending on their functional state. Activation of salivary gland cells with pilocarpin, or of liver cell with prednisolone, equally resulted in a quantitative increase of cells with active (blue) nuclei. Changes in nuclear staining after digestion with trypsin, pronase, or ribonuclease, and after extraction of cellular DNA and RNA with perchloric acid, unequivocally suggest that alteration of the protein-DNA ratio, i.e. the hetero- or euchromatic state of nuclear chromatin, is responsible for the disparity of the nuclear staining reaction with ASTRIN. The new trichrome stain seems to be suitable for routine cytodiagnostic use.