Medium left at room temperature overnight - (Jun/19/2013 )
So we had some RPMI media shipped to us yesterday and everyone in the lab was busy with experiments and we forgot to pick it up from our front office and it sat in there overnight. Now my PI is losing her mind. I keep trying to tell her that it should be fine because that is how it is shipped but can't seem to find anything online to back me up. Can anyone confirm this or possibly point me in the direction of where I could find this info?
There are a few previous discussions that may answer your question
Left my media at room temperature for 48 hours; okay to use?
culture media left out for too long?
ChemDawg, best slution is to ring the company you purchased it from, I did something similar with a reagent (was meant to be in a minus 20 but I left it in a fridge) for fluoresence spectroscopy. Rang the company and they said it's fine, the minus 20 just prolongs it's lifespan, doesn't affect the reagent in the short term. So they will probably be able to assure your PI that the media will be ok...
Mediums usually contains glucose, proteins, Amino acids, vitamins and H2O.
So I guess proteins will be affected if u left it outside in RT if u work in some kind of a very hot African country with temp over 40 C.
but leaving the medium over night for 12 hrs or some thing is ok at normal room temp .
ur medium will not be that hastly deteriorated.
Plus u sometimes leave ur medium outside in the room temp for a couple of hours, if u do some long experiment which needs a lot of time.
I guess putting it in 4 C meant to keep it lasts longer at constant environment.
You will be fine. If there is a problem, the phenol red will let you know. Just explain to your PI that you let your cells incubate in your desired media for multiple days. If it doesn't harm the media at 37C for 3-4 days, why would the media be affected for 24hrs at 25C. I wouldn't recommend you constantly doing this, but the media will be fine. Maybe you can set your PI at ease by aliquoting our 10, 50mL conical vials of your media and take each tube out of the 4C as you need it. This isn't necessary, but it may get you off the hook.
jerryshelly1 on Thu Jun 20 01:54:38 2013 said:
If there is a problem, the phenol red will let you know. Just explain to your PI that you let your cells incubate in your desired media for multiple days. If it doesn't harm the media at 37C for 3-4 days, why would the media be affected for 24hrs at 25C.
Not entirely true unfortunately, phenol red is a pH indicator and nothing else in this case - all it tells you is that the medium hasn't been exposed to the air. Medium contains many heat labile and light sensitive compounds, the most well known of which is L-glutamine. These compounds rapidly degrade on storage without altering the pH. Yes, you do incubate for several days with the medium, but most of these compounds are gone within 12 hours in the dark.
The general rule for work in the lab is: If in doubt, throw it out - you don't trust the medium at the moment, would you trust any results from cells that you used it on? It is far far cheaper and quicker to throw out something dodgy than having to repeat results because you don't trust something you have done/used.