实验一 细菌的分离与纯化.ppt

实验一 细菌的分离与纯化 一、教学要求 通过从土壤、植物中分离纯化细菌，熟练掌握微生物的分离纯化方法和无菌操作技术。 二、实验原理 常用的分离纯化方法 microorganisms exist in nature as mixed populations. However, to study microorganisms in the laboratory we must have them in the form of a pure culture, that is, one in which all organisms are descendants of the same organism. 平板划线示意图 稀释倒平板和涂布法 三、材料与器材 柑橘溃疡病（Xanthomonas axonopodis pv. citri）的病叶、病果。 烟草茎秆 牛肉膏蛋白胨培养基：牛肉膏 3g，蛋白胨 10g，NaCl 5g，Agar 20g，水1000mL，pH7.0-7.2 灭菌水、灭菌培养皿、95% 乙醇、移液器 * 1、单细胞挑取法 简易单细胞挑取法 micromanipulator 2、划线平板分离法 streak plate method The most common way of separating bacterial cells on the agar surface to obtain isolated colonies is the streak plate method. It provides a simple and rapid method of diluting the sample by mechanical means. As the loop is streaked across the agar surface, more and more bacteria are rubbed off until individual separated organisms are deposited on the agar. After incubation, the area at the beginning of the streak pattern will show confluent growth, while the area near the end of the pattern should show discrete colonies. 3、倒平板法pour plate method Another method of separating bacteria is the pour plate method. With the pour plate method, the bacteria are mixed with melted agar until evenly distributed and separated throughout the liquid. The melted agar is then poured into an empty plate and allowed to solidify. After incubation, discrete bacterial colonies can then be found growing both on the agar and in the agar. 4、涂布法spread plate method The spin plate method involves diluting the bacterial sample in tubes of sterile water, saline, or broth. Small samples of the diluted bacteria are then pipetted onto the surface of agar plates. A sterile, bent-glass rod is then used to spread the bacteria evenly over the entire agar surface. 四 操作步骤 制备稀释液 倾注平板 培养 　接种和分离工具 1．接种针 2.接种环 3.接种钩 4.5.玻璃涂棒 6.接种圈 7.接种锄 8.小解剖刀 挑菌落