A supravital cytodiagnostic stain for urinary sediments.

A mixture of aqueous solutions of National fast blue, a copper-phthalocyanine dye, and pyronin B, a red xanthene dye, when added to fresh urinary sediment, supravitally stains benign or malignant cells and the various types of casts and their inclusions. The stain facilitates identification of the formed elements and particularly aids in the differentiation of polymorphonuclear leukocytes from lymphocytes, histiocytes, plasma cells, and renal tubular cells. A variable staining of casts and their inclusions has been observed. Tumor cells may be recognized by nuclear abnormalities or, in case of hyperchromatic tendency, by a very rapid and early uptake of dye preceding that of the surrounding cells. The staining method is rapid and simple enough for routine urinalysis and screening procedures.