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Freshly prepared RPMI plus SERUM= Colour change??? - (Nov/14/2013 )


I have never prepared RPMI plus serum on my own. The techniciam that always prepares it gets pinkish/red medium after mixing serum and RPMI. Well, I went to do it yesterday and my medium turned orange!

What do I do now? Is it contaminated? I just opened the RPMI and the a new bottle of serum...

ANY help will be appreciated!


You just shocked the system. When I add antibiotic to my tissue culture media (DMEM), I see an immediate color change. After letting the media sit for ~12hrs, the color is restored. You just need to keep in mind that pH indicators are present in the media and when a solution is added, it needs to fully equilibrate. I wouldn't worry as long as you followed the protocol.


Try gently mixing the solution or placing it in a water bath for about 30mins.