Bradbury W C, Murray R G, Mancini C, Morris V L
J Clin Microbiol. 1985 Jan;21(1):24-8. doi: 10.1128/jcm.21.1.24-28.1985.
Chromosomal DNAs of selected Bacteroides organisms whose relatedness had been previously determined by "conventional" filter-annealing studies (J. L. Johnson, Int. J. Syst. Bacteriol. 28:245, 1978) were further analyzed by restriction endonuclease analysis coupled with the Southern hybridization procedure (E. M. Southern, J. Mol. Biol. 98:503, 1975). By comparing their EcoRI restriction fragment patterns in agarose gel electrophoresis, each Bacteroides strain could be clearly differentiated. As a simple and direct means for comparison purposes this method was particularly useful for differentiating genetically similar organisms such as Bacteroides strains of the same species which shared greater than 75% homology. In contrast, bacterial chromosomal restriction endonuclease analysis in conjunction with Southern hybridizations was most effectively used to determine the significance of low levels of homology (less than 24%) as this technique provided additional information on the nature and relative distribution of that homology when the areas of homology were displayed as reproducible bands in autoradiograms.
先前通过“传统”滤膜退火研究（J. L. 约翰逊，《国际系统细菌学杂志》28:245，1978年）确定了亲缘关系的所选拟杆菌属生物体的染色体DNA，通过限制性内切酶分析结合Southern杂交程序（E. M. 萨瑟恩，《分子生物学杂志》98:503，1975年）进行了进一步分析。通过比较它们在琼脂糖凝胶电泳中的EcoRI限制性片段模式，每个拟杆菌属菌株都可以被清楚地区分。作为一种用于比较目的的简单直接方法，该方法对于区分遗传相似的生物体特别有用，例如具有大于75%同源性的同一物种的拟杆菌属菌株。相比之下，细菌染色体限制性内切酶分析结合Southern杂交最有效地用于确定低水平同源性（小于24%）的意义，因为当同源区域在放射自显影片中显示为可重复的条带时，该技术提供了关于该同源性的性质和相对分布的额外信息。
