Australia's Science Forum

Just wondering how long you keep agar plates? i.e. how long before they are required do you make them up? I remember making them and storing them in the fridge but can't remember how long before the prac.

Thanks

I usually make them the day before. BUT it is not necessary, as I have made them and stored them in the fridge for weeks and they are OK to use.

Hi
From my lab days and TAFE they should be made 24 hours ahead and incubated at 37 degrees as a sterility check for 24 hours. This is to ensure there is no contamination or growth. They can be wrapped in glad wrap and stored upside down in the fridge to prevent them from drying out.

I get the order, I make them the day before.....they get used up to weeks after as no one is organsied...thats how it works here!

Narelle01 wrote:I get the order, I make them the day before.....they get used up to weeks after as no one is organsied...thats how it works here!

Love it! And can so relate to it!

in a time long, long ago,
agar plates were a regular necessity. but we'd make a batch of agar, store in little bottles, capacity of 1 plate and store in fridge. when you needed them you'd grab the number reqd, heat in water bath, pour into petri dishes and away you'd go.
at another location, we'd just pour the plates and store upside down in fridge until needed. make sure you get them to room temp before using. you can also set one up as control each time to check for contamination.
ensuring aseptic technique of course.

Sharon

has anyone used the parafilm paper instead of agar? does it work and how?

http://www.youtube.com/watch?v=f47Hq2uiJIs

Is this what you mean, Sunray18?

very goos.

I buy my plates and have stored left over plates for over 1 year in the fridge. They have worked fine.

mine are STILL in the fridge - some were used though. 90 were ordered 90 were made....

I try to have them used within a week, but sometimes they are kept for longer. It depends on the thickness of the agar, if too thin then they can dry out and curl up at the sides which is no good. When filling the plates, fill them to about 2/3 full.