实验四 培养基的制备和灭菌（Experiment four preparation and sterilization of culture medium）.doc

实验四 培养基的制备和灭菌（Experiment four preparation and sterilization of culture medium） Experiment four preparation and sterilization of culture medium I. requirements 1. Understand and master the preparation and packing method of culture medium 2 、 grasp all kinds of laboratory sterilization methods and techniques Two. Basic principles The medium is a mixture of nutrients for growth, reproduction, and metabolism of microorganisms. Because microorganisms have different nutritive types, the nutrient requirements are different, and the experiment and research for different purposes, so many kinds of culture medium, the use of raw materials is also different, but from the angle of nutrition analysis, medium containing necessary microbial carbon source, nitrogen source and inorganic salt auxin and water, etc.. In addition, the medium should have suitable pH value, a certain buffer capacity, a certain redox potential and appropriate osmotic pressure. Agar is colloidal substance obtained from agar and other algae, is the most widely used coagulant. Agar medium was thawed at 98~100 degrees Celsius and solidified at 45 degrees celsius. But after repeated melting, the solidification is reduced. Any kind of culture medium should be sterilized thoroughly in time, so as to prepare pure culture. The sterilization of common medium was performed by autoclave. Three, equipment 1, solution or reagent peptone, NaCl, K2HPO4, agar, NaNO3, KCl, MgSO4, FeSO4 and so on, see the formula of culture medium. 2, the instrument or other appliances, electronic balance, high-pressure steam sterilization pot, weighing paper, horn spoon, pH test precision, scale cylinder, enamel cup, tube, flask, funnel, rack, pipettes and pipette barrel, Petri dishes, beaker, glass rod, tube frame, alcohol lamp, electric furnace etc.. Four, operation steps The basic process is called medicine, dissolution, adjustment, pH value, melting agar, filtering, packing, marking, sterilizing, swinging, inclined or falling flat. 1, w