Many people do not understand why peptone and sodium chloride should be added while doing the beef extract medium test. Different formulations have different additives, in fact, in addition to the process of melting beef paste need to add peptone and sodium chloride, there are many medium formulations also peptone and sodium chloride addition. So what is the effect of adding peptone and sodium chloride?
Peptone: provide nitrogen source to microorganisms, peptone is a nitrogen source product easy to absorb by microorganisms, with small molecule and strong permeability. It is the main nutrient source of microorganisms.
Sodium chloride: mineral supplements, the most important role is to buffer, we know that human body fluid osmotic pressure is 0.85--0.9%, with sodium chloride solution, configured to be similar to the human body osmotic solution, effective To alleviate the stress of somatic cells, if it is a microbial culture medium, the osmotic pressure data of the microorganisms should be taken into consideration to prepare a reasonable culture medium.