FLUORESCENCE OF MAST-CELL GRANULES IN PARAFFIN SECTIONS AND CELL SMEARS INDUCED BY N-QUATERNARY OXAZOLE SCINTILLATOR

The N-quaternized derivative of dimethyl-POPOP (termed Q4) induces a b luish-green fluorescent reaction in mast cell granules from paraffin s ections and cell smears, in addition to a previously described bluish- white fluorescent reaction in chromatin DNA. The chromatin reaction wa s abolished by staining the samples either with Mayer's Haematoxylin b efore Q4 treatment or by Q4 treatment at pH 1.5. The reaction in mast cell granules was absent after substrate methylation. The staining seq uence Haematoxylin-Eosin-Q4 also worked well in paraffin sections, all owing the observation of the current histological image under bright-f ield illumination as well as double-colour emission under fluorescence microscopy. The sequence is proposed as a new diagnostic procedure fo r demonstrating mast cell granules.