AbstractWe developed a method to facilitate measurements of aluminum (Al) positive lines in bone biopsies from patients with renal osteodystrophy by modifying solochrome azurine (SA) methods for tissue A1 staining so that background staining of calcium (Ca) deposits, soft tissues, and glycol 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 characteristics at various pHs of each component in histologic sections and of the solubility of the resulting SA-complexes in aqueous and alcoholic solutions indicated that optimal staining of A1 deposits could be obtained by staining GMA embedded sections for 16 hr at pH 5. Subsequent destaining with deionized water, ethylenediaminetetraacetic acid (EDTA), and deionized water removed background staining without loss of A1 staining. Sections prepared by these methods were satisfactory for obtaining, enhancing, and measuring Al-positive lines with semi-automated programs designed for use with the Image 1 Video Image Analysis. Measurements obtained in this way are as reproducible and precise but faster than manual methods for measuring A1 lines, and, therefore, are an improvement in the methodology for measuring A1 lines in bone biopsies from patients with renal osteodystrophy or other bone diseases. (The J Histotechnol19:115, 1996)