Shelf Life of prepared Media!

[MissJasmine]

Hi Everyone!

 

Does ANYONE have a link to a chart or happen to know the shelf-life of various prepared media?

I work in a micro lab, and sometimes like to make plates before I'll need it (even months)

 

I'm aware that TSA, TSB, NUTRIENT AGAR AND NUTRIENT BROTH all have a prepared medium life span of 6months+, however what about the following media:

 

-Spirit Blue Agar

-MacConkey

-Hektoen

-Mannitol Salt Agar

-Urea Broth

 

Thanks a Bunch,

 

Jasmine

[CharonY]

It depends a lot on storage conditions (temperature, light exposure, airtight seal etc.) and what type of bacteria you grow on them and for what purpose. Shelf life is only a very rough estimate at best. As a rule of thumb, minimal media that contain only little to no complex components such as peptides amino acids, vitamis etc. tend to be stable for a very long time. The issue with plates is that they have to be very tightly sealed, otherwise they lose water, obviously.

But even with a certain amount of degradation some bacteria are robust enough to handle it. Others are a bit more sensitive and may exhibit changes in growth (or do not grow at all). In the end, there is no fixed expiration date, but for more sensitive (must not fail) assays, fresh plates are a better idea, for standard cultivation storing a few months under appropriate conditions are usually not an issue.