Adding phenol red to media - medium (Jul/09/2008 )
I prepared phenol red-free media before realizing that I need the phenol red. Can I simply add phenol red to the solution for use as culture media? Typically we use DMEM + 10% FBS. I want to use DMEM, serum-free, so I need the phenol red as a pH indicator. Any help is appreciated.
You don't really need the phenol red, you just have to keep a bit more of an eye on your cells to prevent the medium from being depleted. Having said that, you should be able to just add phenol red to your medium, taking appropriate sterility precautions, of course.
That is, unless you are doing some expression profile/proteomics study where comparability between previous and planned experiments/datasets is important.
In that case, you need to find out what exact recipe was used. Some are here anyways:
If the only reason you need the phenol red, is as a ph indicator so you know when to change the media...
Then you don't need it... Like the first person said, just keep an eye on the cells and replate/passage them when they reach or get near to confluence...
suggest you not shortcut your science. if you past and future experiments include phenol red or if you expect to compare your results in that context, add it. It is a variable and one you can easily eliminate.
Jorge makes a good point, particularly since it is easy to deal with. Just make sure you look at the formulation of the phenol red-containing medium you used previously.
However, there is another, perhaps more important issue. Phenol red possesses some estrogenic activity. In breast cancer research in which estrogenic responses are evaluated or need to be eliminated as a variable, two common/standard ways to eliminate this variable is to use phenol red-free medium and to use charcoal-stripped serum. So, the possibility that phenol red is a source of experimental variablility is a real one.
Best of luck,
Is something to have in mind the phenol red estrogenic effect, you can find lot of papers in which is use in the culture media of neurons and have an effect that is not reported using other medias. U may think: on neurons? yes, of course! even progenitor neurons of hippocamparl dentate gyrus respond to estrogens...
just to remind it.