本实验采用四种方法:(1)冷酚法。(2)琼脂糖凝胶2 B柱层析(3)超速离心。(4)镁离子沉淀,从大鼠肝中分离出poly A RNA。用(1)法提取总RNA,用其他方法分别抽提pRNA,再分别经Oligo(dT)—纤维素柱层析分离出poly A RNA。从A260/A280,A280/A260,A260/A230,比值、收得率、电泳行为作一比较,初步认为:冷酚法所得polg A RNA收得率较好,但有其他RNA;2 B拄层析法收得率最高,可是纯度较差;超离心法仪器昂贵,不宜普及,镁离子沉淀法则是一个操作简便而又适用的方法。
The biosorption capacity differences of copper cation by yeast Candida utilis cells and isolated cell walls were investigated. The results showed that the metal accumulated by cell walls was usually 50% higher than that by intact cells. This suggested that the cell walls of yeast were the main sites for heavy metal accumulation. Treatments of cell wall with proteinases demonstrated that the copper accumulated by trypsin-treated cell walls was almost the same as that by intact cell walls (95%), while the subtilisin-treated cell walls almost lost the potential of metal accumulateion (only 3%), suggesting that the main sites of copper accumulation in Candida utilis cell walls were trypsin-unsensitive integral proteins. Fig 1, Ref
