不同抗原修复方法对肝癌组织中内源性生物素的影响及对策

目的探讨不同抗原修复方法对肝癌组织中内源性生物素的影响以及消除办法.方法采用pH6.0、pH8.0及pH9.0不同pH值的抗原修复液进行修复,对30例经甲醛固定石蜡包埋的肝细胞癌组织中内源性生物素活性进行检测,并通过不同检测方法对30例肝细胞癌中AFP(Alpha Fetoprotein)染色结果进行对比.结果加热抗原修复暴露肝细胞癌组织中内源性生物素的活性.不同pH值抗原修复液对内源性生物素的活性影响各不相同,阳性强度随着pH值增高而增强.生物素阻断剂能有效阻断内源性生物素的活性.采用pH9.0Tris-EDTA进行修复加Envision检测系统可提高肝癌组织中AFP的阳性率及阳性强度.结论加热抗原修复可使被甲醛封闭的内源性生物素的活性重新暴露,对免疫组化的染色结果造成影响,生物素阻断系统是消除内源性生物素的有效方法,采用pH9.0的抗原修复液进行修复加Envision非生物素检测系统是免疫组化染色中较为理想的检测方法.

INFLUENCE OF DIFFERENT HEAT-INDUCED EPITOPE RETRIEVAL METHODS ON ENDOGENOUS BIOTIN IN HEPATOCELLULAR CARCINOMA TISSUES

Objective To investigate the influence of different heat-induced epitope retrieval methods on endogenous biotin, and to establish an effective way to block endogenous biotin in hepatocellular carcinoma. Methods By using the pH6.0, pHS. 0 and pH9.0 buffers, the activity of endogenous biotin in 30 formalin-fixed and paraffin-embedded specimens of hepatocellular carcinoma was examined. The AFP immunohistochemical dyeing results of the 30 samples were compared between different detective methods. Results The activity of endogenous biotin was revealed after the hepatocellular carcinoma tissues were treated with microwave heat-induced epitope retrieval. The higher pH value, the greater effect. It was also discovered that the biotin blocking solution could block endogenous biotin activity. Combined use of pH9.0 Tris-EDTA buffer with Envision detective system could enhance the AFP positive rate and intensity in hepatocellular carcinoma tissues. Conclusion Heat-induced epitope retrieval can unmask endogenous biotin in formalin-fixed tissues and influence the immunohistochemical dyeing results. The biotin-blocking solution can effectively eliminate the effect of endogenous biotin. It is an ideal immunohistochemical method to use pH9.0 buffer combined with Envision non-biotin detective system.