Expired medium - (Oct/17/2014 )

Hi guys,

I want to use RPMI 1640, but the stock we have is almost a year expired ( 3 bottles).

I know what are written in books and manuals about expiration date, but I want to do some experiments just to try, so no need to exhaust our lab budget.

Please do u have any real experience with such situation .

For me I had real experience with expired chemical reagents ( for chemical synthesis), and It went fine during the chemical synthesis of compounds.

But what about expired culture medium?

please if u have experience , share it with us here in bio-forums.

Expired medium will have had all the labile compounds (mostly amino acids, but potentially also vitamins too) degrade by time. This alters the pH of the solution some (not enough to see by phenol red), and means that these compounds are not available to the cells. Having said that I have grown some common cell lines like HeLa on expired medium with no obvious problems... however, this doesn't mean that it is a good idea, especially if you are looking at anything relating to metabolism or growth rates.

You simply buy new culture medium for your research.

I once use expired RPMI-1640 (powder form) to grow my MDCK and Vero cells, they are able to grow just as well.

Did you keep the bottles nicely in cold? 

I suggest you experiment with it first and compare. One year expired is actually quite long.