用^32P后标记法检测固定组织（细胞）及石蜡包埋组织中DNA加成物

32P-POSTLABELLING DETECTION OF DNA ADDUCTS INFORMALIN FIXED AND PARAFFIN-EMBEDED TISSUE SAMPLES

大鼠经腹腔注射不同剂量的Ｂ（ａ）Ｐ４８ｈ后，取出肝脏，分为两半分别在新鲜时及经福尔马林固定后；或在新鲜时及经石蜡包埋后，分别用３２Ｐ后标记法检测其ＤＮＡ加成物，结果分别可分离到１个和５个加成物斑块，其相对加成物标记量（ＲＡＬ））有很好的剂量－效应依赖性关系，经统计学处理后，相同剂量点上加成物的量均无显著性差异（Ｐ＞０．０５）。不同浓度Ｂ（ａ）Ｐ处理后的ＦＬ细胞，再经福尔马林－磷酸盐缓冲液固定后，可分离到４个加成物斑块，其ＲＡＬ有良好的剂量－效应依赖性关系。提示；固定组织（细胞）和石蜡包埋组织中ＲＮＡ加成物的定性和定量均无明显的变化；３２Ｐ后标记法亦可运用于固定组织（细胞）和石蜡包埋组织中ＤＮＡ加成物的检测。

In male SD rats,one i.p.administration of different dosc of B(a)P were given.48 hours later,then livers were removed,and each liver was divided into two halves.One was kept freshly,the other half was fixed with formalin,or in other group furthermore was embeded in paraffin.One or five adduct spots were found by 32P-postlabeling assay,and the relative adduct labeling(RAL)hada good dose-response relationship,respectively.Similarly,four adduct spots were found in formalin-PBS fixed FL cells which had been treated with B(a)P,and the total RALs also had a clear-cut dose-response relationship.No significant difference can be found in both qualitative and quantitative(P>0.05)detcction of DNA adducts between fresh tissues(cells)and formalin-fixed tissues(cells)or paraffin-embeded tissues.These results indicated that DNA adducts preserved well in tissues and cells after formalin fixation and paraffin embeding,and also indicated that 32P-postlabeling method was applicable to not only fresh tissues(cells),but also fixed and paraffin-embeded tissue samples.