条斑紫菜高纯度总DNA及其质粒状DNA的提取

Extraction of plasmid-like DNA and high-quality total DNA from Porphyra yezoensis

提取条斑紫菜高纯度总ＤＮＡ及其质粒状ＤＮＡ的新方法．先用海螺酶处理 紫菜叶状体制备细胞，然后用ＳＤＳ－蛋白酶Ｋ裂解细胞提取总ＤＮＡ，再用玻璃粉浆 （ｇｌａｓｓｍｉｌｋ）对其纯化，经纯化后的总ＤＮＡ能被ＥｃｏＲＩ，Ｄｒａｌ与ＨａｅⅢ等限制酶完全酶 切，并在酶切图谱上形成明显的ＤＮＡ带型．当用异硫氰酸胍一十二烷基肌氨酸钠裂 解紫菜细胞时，在总ＤＮＡ提取物中直接发现有一条质粒状ＤＮＡ带（２．３ Ｋｂ），即建 立了一种极简便的质粒状ＤＮＡ提取方法．

Cellls were prepared from sea snail enzyme digests of Porphyra yezoensis Thalli. Crude extracts of total DNA were isolated from Porphyra cells lysed with SDS - Proteinase K solution. Total DNA was purified with glassmilk, the resulting DNA was of high quality, could be completely digested with restriction enzymes. So that it was also suitable for analyses of Southern hybridization, RFLP and ALP, etc. DNA bands were clearly observed in the agarose gel electrophoresis patterns of total DNAs digested with EcoRI, PstI and HaeⅢ respectively. The presence of DNA bands in the electrophoresis patterns of total DNA showed that the nuclear genome of Porphyra yezoensis may be small. Unexpectedly, a plasmid-like DNA band (2. 3Kb) was found in the electrophoresis pattern of P. yezoensis total DNA isolated with guanidinium thiocyanate-sarcosyl solution. This is a very simple and convenient method for plasmid-like DNA isolation.