【摘要】 采用国产电子显微镜和旋转投影设备,通过一步释放或二步释放的蛋白单分子层电子显微镜技术,分别对谷氨酸生产菌——北京棒状杆菌(Corynebacterium pekingnesis AS 1.299)的DNA噬菌体A3、大肠杆菌(E.coli)一些菌系的RNA噬菌体C2和f2以及青霉素生产菌产黄青霉菌(Penicillium chrysogenum P001)的RNA病毒P.C.颗粒释放的核酸进行了观察,并对噬菌体A3的变性分子、再生分子以及释放的自然DNA分子的形状进行了比较。结果指出,C2,f2 噬菌体和病毒P.C.的核酸用一步法释放出来,特别是f2噬菌体释放率较高。用二步法(高pH或5M尿素预处理)能将噬菌体 A3 DNA 分子释放出来,其释放的自然分子绝大多数呈现长线状,而变性分子呈单股树丛状,再生分子呈多中心、双中心、单中心、扩展(无中心)、长线伏、环形、分叉,并在双股DNA分子上还呈现单股树丛状、环形和单股分叉等物理特性。更多还原

【Abstract】 With the aid of an electron micros-cope and a rotation shadowing attach-ment, both made in China, visualizationof nucleic acid released from A3 DNAphage of Corynebacterium pekingnesisAS 1.299, C2 as well as f2 RNA phagesof certain E. coli strains and virus ofPenicillium chrysogenum strain P001were made by means of the proteinmonolayer technique adopted for one andtwo steps nucleic acid releasing methods.An electron microscopic comparison wasmade between the native and the dena-tured, annealed molecules released fromA3 phage. It was shown that the nuc-leic acids of C2 and f2 phages as well asvirus P. chrysogenum could be releasedby the one step method, that of C2being the easiest. The DNA in phageA3 could be released by the two stepmethods with a prior treatment with analkaline pH or a 5M urea solution atroom temperature. The DNA releasednaturally assumed a linear configuration.The denatured molecules appeared onlysingle-strand bushy, and the renaturedmolecules were multi-centered, double-centered, mono-centered, extended (wi-thout any center), looping or branched.The double stranded DNA molecules mayalso exhibited single strand looping, bu-shy or branching.更多还原