A Modification of the Tannic Acid Phosphomolybdic Acid-Dye Stain for Demonstrating Myoepithelial Cells in Formalin Fixed Tissue

A modified tannic acid-phosphomolybdic acid-dye procedure is used for staining myoepithelial cells in formalin fixed surgical and autopsy material. Paraffin section are brought to water, mordanted for 1 hr in Bouin's fixative previously heated to 56 C, cooled while still in Bouin's, rinsed in tap water until sections are colorless, rinsed in distilled water, treated with 5% aqueous tannic acid 5-20 min, rinsed in distilled water 30 sec or less, treated with 1% aqueous phosphomolybdic acid 10-15 min, rinsed 30 sec in distilled water, rinsed in methanol, stained 1 hr in a saturated solution of amido black or phloxine B in 9:l methanol:acetic acid, rinsed in 9:l methanol:acetic acid, dehydrated, cleared and mounted. Myoepithelial cells of sweat, lacrimal, salivary, bronchial, and mammary glands are blue-green with amido black or pink with phloxine B. Fine processes of myoepithelial cells are well delineated. Background staining is minimal and the procedure is highly reproducible.