革兰氏染色革兰氏染色实验目的1. 学习并掌握革兰氏染色2. 理解革兰氏染色原理3. 巩固显微和无菌操作技术实验步骤1. 制片 将生长旺盛时期的细胞用常规方法涂片（不应太厚），干燥、固定。2. 初染 滴加草酸铵结晶紫覆盖细菌的涂层，1-2 分钟，倾斜玻片，用水冲洗至无色3. 媒染 先用卢卡氏碘液冲掉残余水分，然后用碘覆盖 1 分钟，倾斜玻片，用水冲洗至无色4. 脱色 用吸水纸吸去残余水分，在白色背景下使用 95%乙醇脱色（通常20-30 秒），当流出水无色时立刻用水冲洗乙醇。5. 复染 用吸水纸吸净水分，番红染液染色 2min，用水冲洗至无色。6. 镜检 油镜观察7. 混合涂片染色 在同一区域内将大肠杆菌和金黄色葡萄球菌混合涂片，其他步骤同上。实验结果大肠杆菌呈杆状，说明大肠杆菌是革兰氏阴性（G-）细菌。金黄色葡萄球 菌呈球形，革兰氏染色后的颜色为蓝色，说明金黄色葡萄球菌是革兰氏阳性 （G+）细菌。Gram stainExperimental purposes1. Learn and master the Gram stain.2. Understand the principles of Gram stain.3. Consolidate microscopy operation techniques and aseptic technique.Steps1. producerTake an active growth phase bacteria by conventional methods of smear(should not be too thick), dried and fixed.2. primary stainPlus ammonium oxalate crystal violet dye covering bacteria coated , dyeing 1-2min, tilting to the dye, washed out of the water to colorless.3. mordantingFirst used Lugol iodine washed out residual traces of water, then iodine covered 1min, tilting to the iodine, washed out of the water to colorless.4. destainingResidual water on the slide with absorbent paper absorbed, on a white background use dropper flow plus 95% ethanol bleaching(Usually 20 30s),when the outflow of water was colorless as soon as wash with water liquid ethanol.5. counterstainResidual water on the slide with absorbent paper absorbed, stained with safranin counterstain 2min, washed, absorb residual water to dry.6. microscopic examinationObserve oil microscope.7. mixed smear dyeingIn same area on slide Escherichia coli and Staphylococcus aureus are mixed smear, other steps like as above.Experimental resultsE. coli is rod-shaped, after the gram stain colour to red, description the E.coli is gram-negative (G-) bacteria. Staphylococcus aureus is a spherical shape,after the gram stain colour to Blue, description the Staphylococcus aureus is gram-positive (G +) bacteria.