The use of Mallory's phosphotungstic acid-hematoxilin (PTAH) stain in renal pathology.

High quality histology is needed in renal biopsy examination, especially when material for immunofluorescence and/or electron microscopy is not available. For these purposes Mallory PTAH stain was tried on 34 renal biopsies and the results were compared with the immunofluorescent and ultrastructural findings (used as a control of the reliability of the method). PTAH, besides showing extracellular structures, cytological details and rather subtle abnormalities, was able to detect the presence and the site of deposits. PTAH stains the material which appears as electron dense deposits in electron microscopy and as granular deposits in immunofluorescence, whereas it fails to stain linear deposits in immunofluorescence (which are not electron dense). Moreover, a good correspondence between PTAH and electron microscopic data was detected as far as the location of deposits is concerned.