[A new embedding material for morphometry: Shiojirin E-10].

Abstract

For morphometric studies, sections have been stained with the Luxol fast blue-PAS-Hematoxylin (LPH) staining method after secondary fixation with chromic acid followed by embedding in Celloidin to measure the area of nerve cells or axons with the help of an image analyzer and a microscope. However, the manufacture of Celloidin has been suspended in Japan. Therefore, we studied the use of Shiojirin E-10 (10% nitrocellulose ether alcohol solution) as a substitute embedding material, and compared it with Celloidin from the viewpoint of tissue shrinkage and staining characteristics. Regarding the shrinkage ratio of LPH-stained sections of human cauda equina, there was no practical difference in the axonal areas (p < 0.01) between Celloidin sections (4.31 +/- 2.55 microns2) and Shiojirin E-10 sections (4.14 +/- 2.20 microns2). Regarding staining characteristics, we introduced a hue analysis method using computerized digital signals converted from pictures of stained sections taken by a videocamera. For the evaluation of hue, we examined the H-E sections of mouse liver and kidney, and the LPH sections of the human cauda equina. The hematoxylin hues of the H-E sections were 295 degrees for Celloidin and 294 degrees for Shiojirin E-10. Eosin hues of the E-E sections were 320 degrees for both embedding material. The axonal hues of the LPH stain were 254 degrees for Celloidin and 251 degrees for Shiojirin E-10. Myelin sheath hues were 224 degrees for both embedding material. According to our results, Shiojirin E-10 can be substituted for Celloidin from the qualitative and quantitative viewpoints in the morphologic studies.