A Well Stored Culture Medium Is Important For the Success of Every Microbiology Experiment

By definition, microbiology is a branch of science that deals with the study of micro-organisms either at a single cell or multi cellular level. For the study of micro-organism, they are first isolated, and then multiplied in a controlled laboratory conditions to produce a culture of the organism.

What Is A Culture?

A culture of micro-organism like yeast, bacteria, moulds, fungi, etc. has the specific micro-organism in abundance, which is required for any kind of testing or experiment. A pure culture has only a specific micro-organism without any traces of others organisms.

This is not how these micro-organisms exist in nature normally, and thus these have to be stored and maintained carefully to retain their purity. A viable culture medium should facilitate the growth of the micro-organism in a controlled way.

What Are The Main Ingredients Of A Microbiological Culture?

Its main objective is to create the right environment for the rapid growth of the micro-organism. By the guidelines laid down by ISO 11133-1, it should have nutrients, salt, source of energy, enrichment, antioxidants, neutralising agents, reducing agents, pH-regulators and chromogenic nutrients.

In addition to these, for stable culturing, there must be presence of selective agents that will help in suppressing the growth of any other micro-organism other than the one that is specifically required in it.

How to Store a Culture Medium?

Proper storage is very important to maintain the viability of the culture medium. The following points must be kept in mind while storing it:

• To store the dehydrated culture mediums, the room temperature of 10-30 degree C is ideal. A ready to use culture, however, has to be stored at 2-4 degree C.
• They should be stored in a completely dry place away from sunlight or any other source of heat.
• Avoid any sudden and extreme changes in temperature as this would spoil the culture medium.
• Its shelf life reduces with each time the bottle is opened, and thus it is suggested that you avoid exposing the culture to the atmosphere again and again.
• Store it in smaller container that has the volume of 2-3 usage only. This way you can avoid frequent opening of bigger containers.
• Close the lid of the bottle tightly to protect it from getting effected by the environment.
• Avoid absorption of moisture by dehydrated cultures and condensation in ready to use culture mediums.
• Store them in such a way that you can read the labels easily, and you don’t have to move them around too much to find the one you want.
• Discard all products that fail to match specifications.
• Its typical shelf life is around 3 to 5 years. All cultures, which are past their expiry date, should be discarded.
• While opening the container, ensure that there is no moisture. Avoid inhaling and touching the culture with your bare hands.

When stored properly, a culture medium can easily last its entire shelf life. However, each time you use it, make sure that it is in good condition, and as per the required specifications.