MODIFIED ACIDIC SOLOCHROME AZURINE STAIN FOR VIDEO IMAGE-ANALYSIS OF ALUMINUM LINES IN BONE BIOPSIES

We developed a method to facilitate measurements of aluminum (Al) posi tive lines in bone biopsies from patients with renal osteodystrophy by modifying solochrome azurine (SA) methods for tissue Al staining so t hat background staining of calcium (Ca) deposits, soft tissues, and gl ycol methacrylate (GMA) did not interfere with gray level thresholding of Al-positive deposits in video images processed by a semiautomated image analysis system. Detailed studies of the SA staining characteris tics at various pHs of each component in histologic sections and of th e solubility of the resulting SA-complexes in aqueous and alcoholic so lutions indicated that optimal staining of Al deposits could be obtain ed by staining GMA embedded sections for 16 hr at pH 5. Subsequent des taining with deionized water, ethylenediaminetetraacetic acid (EDTA), and deionized water removed background staining without loss of Al sta ining. Sections prepared by these methods were satisfactory for obtain ing, enhancing, and measuring Al-positive lines with semi-automated pr ograms designed for use with the Image 1 Video Image Analysis. Measure ments obtained in this way are as reproducible and precise but faster than manual methods for measuring Al lines, and, therefore, are an imp rovement in the methodology for measuring Al lines in bone biopsies fr om patients with renal osteodystrophy or other bone diseases.