Barker G R, Cordery C S, Jackson D, Le Grice S F
J Gen Microbiol. 1979 Apr;111(2):387-96. doi: 10.1099/00221287-111-2-387.
Minicells segregated from Escherichia coli chi925 carrying a drug-resistance plasmid were separated from nucleated cells by differential centrifugation and purified by rate-zonal centrifugation in sucrose gradients. Minicells purified in this way were capable of donating the plasmid to nucleated cells. They also incorporated thymidine, uridine and methionine into macromolecules. Methods are described for purification of plasmid-containing minicells on a scale large enough to allow isolation of DNA, DNA polymerase and RNA polymerase in sufficient quantities for studies of enzymes involved in replication and transcription of plasmid DNA.
从携带耐药质粒的大肠杆菌chi925中分离出的微细胞，通过差速离心与有核细胞分离，并在蔗糖梯度中通过速率区带离心进行纯化。以这种方式纯化的微细胞能够将质粒传递给有核细胞。它们还能将胸苷、尿苷和甲硫氨酸掺入大分子中。本文描述了一种大规模纯化含质粒微细胞的方法，该方法能够获得足够数量的DNA、DNA聚合酶和RNA聚合酶，用于研究参与质粒DNA复制和转录的酶。
