Kiernan J A
Department of Anatomy and Cell Biology, University of Western Ontario London Canada N6A 5C1.
Biotech Histochem. 2004 Oct-Dec;79(5-6):203-10. doi: 10.1080/10520290400018005.
Hexazonium pararosaniline is a valuable reagent that has been used in enzyme activity histochemistry for 50 years. It is an aqueous solution containing the tris-diazonium ion derived from pararosaniline, an aminotriarylmethane dye, and it contains an excess of nitrous acid that was not consumed in the diazotization reaction. Other investigators have found that immersion for 2 min in an acidic (pH 3.5) 0.0015 M hexazonium pararosaniline solution can protect cryostat sections of unfixed animal tissues from the deleterious effects of aqueous reagents such as buffered solutions used in immunohistochemistry, while preserving specific affinities for antibodies. In the present investigation hexazonium pararosaniline protected lymphoid tissue and striated muscle against the damaging effects of water or saline. The same protection was conferred on unfixed sections treated with dilute nitrous or hydrochloric acid in concentrations similar to those in hexazonium pararosaniline solutions. Model tissues (solutions, gels or films containing gelatin and/or bovine albumin) responded predictably to well known cross-linking (formaldehyde) or coagulant (mercuric chloride) fixatives. Hexazonium pararosaniline solutions prevented the dissolution of protein gels in water only after 9 or more days of contact, during which time considerable swelling occurred. It is concluded that there is no evidence for a "fixative" action of hexazonium pararosaniline. The protective effect on frozen sections of unfixed tissue is attributable probably to the low pH of the solution.
副蔷薇苯胺六甲铵是一种重要的试剂，已在酶活性组织化学中使用了50年。它是一种水溶液，含有源自副蔷薇苯胺（一种氨基三芳基甲烷染料）的三重氮离子，并且含有过量的在重氮化反应中未消耗的亚硝酸。其他研究人员发现，将未固定的动物组织的低温恒温器切片浸入酸性（pH 3.5）的0.0015 M副蔷薇苯胺六甲铵溶液中2分钟，可以保护其免受免疫组织化学中使用的水性试剂（如缓冲溶液）的有害影响，同时保留对抗体的特异性亲和力。在本研究中，副蔷薇苯胺六甲铵保护淋巴组织和横纹肌免受水或盐水的破坏作用。用浓度与副蔷薇苯胺六甲铵溶液相似的稀亚硝酸或盐酸处理的未固定切片也具有同样的保护作用。模型组织（含有明胶和/或牛白蛋白的溶液、凝胶或薄膜）对众所周知的交联剂（甲醛）或凝固剂（氯化汞）固定剂有可预测的反应。副蔷薇苯胺六甲铵溶液仅在接触9天或更长时间后才防止蛋白质凝胶在水中溶解，在此期间会发生相当大的膨胀。得出的结论是，没有证据表明副蔷薇苯胺六甲铵有“固定”作用。对未固定组织冷冻切片的保护作用可能归因于溶液的低pH值。
