中文摘要：

目的：观察免疫荧光技术中不同固定剂对SGC7901细胞中RhoA蛋白定位的影响，找出最适合观察RhoA蛋白细胞内定位的固定方法。方法：采用免疫荧光的方法观察在使用不同固定剂（2％多聚甲醛，4％甲醛，甲醇，丙酮，10％三氯醋酸）及0．3％TritonX-100穿孔的条件下，RhoA蛋白在SGC7901细胞中的定位。结果：用2％多聚甲醛固定，不用0．3％TritonX-100时，染色显示胞质内可见少量RhoA蛋白散在分布，核内则有RhoA蛋白浓聚；用0．3％TritonX-100后，质内只能见极少量阳性染色，核内蛋白染色变得清晰。甲醛固定后染色显示RhoA蛋白主要在核内分布，使用TritonX-100后染色更为清楚。甲醇和丙酮固定后染色显示RhoA蛋白主要在胞质内分布，核内基本未见阳性分布，加TritonX-100后核内染色增强，胞质染色减弱。另外，使用10％三氯醋酸固定未加TritonX-100时染色较淡，胞质胞核都可见，加TritonX-100后核内可见蛋白浓聚，胞质染色减少。结论：用免疫荧光法观察RhoA定位时，固定剂的不同以及是否加TritonX-100对观察RhoA蛋白细胞内定位具有较大的影响。

英文摘要：

Objective： To observe the effect of different fixatives on the location of RhoA protein and find the optimum fixative for the localization of RhoA in SGC7901 ceils by immunofluorescence microscopy. Methods： The subcellular location of RhoA protein in cultured SGC7901 cells fixed with different fixatives such as 2% paraformaldehyde, 4% formaldehyde, methanol, acetone, and 10% trichloroacetic acid （TCA） was studied by immunofluorescence microscopy. Results： Cells fixed by 2% paraformaldehyde without TritonX-100 treatment showed accumulation of RhoA in nucleus but little distribution in cytoplasm. After penetrating with TritonX-100, RhoA protein could not be detected in cytoplasm and was more accumulated in nucleus. Cells fixed by 4% formaldehyde without TritonX-100 penetrating showed nuclear distribution of RhoA. After penetrating with TritonX-100, the staining became clearer. Fixation of SGC7901 cells with methanol or acetone without TritonX-100 penetrating showed that RhoA distributed mainly in the cytoplasm. After penetrating with TritonX-100, RhoA staining could be seen in nucleus and became weaker in cytoplasm. In addition, in cells fixed by 10% TCA without TritonX-100 penetrating, RhoA was stained blurredly and could be seen in both cytoplasm and nucleus. After TritonX-100 penetrating, the staining became clear and the distribution was reduced in cytoplasm and increased in nucleus. Conclusion： Different fixatives and penetrating with TritonX-100 or not are important for localizing RhoA protein by immunofluorescence microscopy.