@article{oai:shinshu.repo.nii.ac.jp:00002062,
 author = {武井, 則之 and 安東, 基善 and 長谷川, 博雅 and 川上, 敏行 and 枝, 重夫},
 issue = {2},
 journal = {松本歯学},
 month = {Aug},
 note = {The silver impregnation method for nucleolar organizer regions (Ag-NORs) was developed by Howell and Black (1980), and their one-step method is thought to be quiet useful as a marker of proliferation activities of cells. However it had a tendency to cause contamination due to non-specific absorption and precipitation of silver dots on the surface of the specimens. Therefore, the purpose of the present article is to evaluate the best method for the demonstration of Ag-NORs proteins using two materials; one is hyperkeratosis, and the other is squamous cell carcinoma. The original and modified methods used and the staining results are as follows: The original method was performed according to the Howell and Black method. AgNORs staining solution was prepared by dissolving gelatin in 1% aqueous formic acid at a concentration of 2%, this solution was mixed, 1:2 volumes, with 50% aqueous silver nitrate solution (this solution was freshly made at each time, filtered through a 0.02μm Millipore filter, Millex-GV^[○!R]: JAPAN MILLIPORE, Ltd., Tokyo), to create the final working solution. This was poured over the tissue sections and left for 25 minutes under safetylight conditions. These specimens were washed off for 15 minutes with running water. Counter staining was not used, and they were dehydrated and mounted. Staining results were difficult to discriminate construction like-mass from microscopic silver dots. However this method had a tendency to contaminate much of the surface of the specimens. The fixing method was used the same Ag-NORs solution as the original one. Tissue sections had the Ag-NORs solution poured upon them and left for 25 minutes under safetylight conditions. After washed off with running water, they were dipped into a 5% sodium thiosulfate pentahydrate solution and left for 5 seconds. Finally they were washed off for 15 minutes with running water, dehydrated and mounted. According to the results, it was considered possible to observe correct Ag-NORs by eliminating excessive absorption and precipitation of silver dots by 5% sodium thiosulfate pentahydrate solution. The next method, called the substitution method, substituted gold chloride acid tetrahydrate for silver nitrate. Therefore tissue sections had the same Ag-NORs solution poured on them just specimens as the former and were left for 25 minutes. After being washed off with running water, these were dipped into 0.1% gold chloride acid tetrahydrate solution and left for 5 seconds. After wards, these were washed with running water, dehydrated and mounted. These procedures were carried out under safetylight conditions. The results of this method are as follows. Althogh it is comparatively easy to observe microscopic silver dots, this staining contaminates the surface of many specimens, and this tendency was very similar to the original method. The fixing-substitution method is as follows; after fixation the tissue sections had the same Ag-NORs solution poured them as on the former specimens and left for 25 minutes. After washed off with running water, these were dipped for 5 minutes into 5% sodium thiosulfate pentahydrate solution and washed off with running water, and dipped for 5 seconds into 0.1% gold chloride acid tetrahydrate solution. Then, these were washed off for 15 minutes with running water, dehydrated and mounted. We suspected that this method was able to discriminate between microscopic silver dots and construction like-mass. No contaminations were observed on the surface of these specimens. It may be concluded that this method may prove to be better than other three methods., application/pdf},
 pages = {172--179},
 title = {核小体形成体のための鍍銀染色法の検討},
 volume = {20},
 year = {1994}
}