geneticin in RPMI medium, color change to yellow - (Oct/23/2006 )
I did realize this color change for a while and seems the cells grow ok. I just wondered that do you guys just grow cells in it or you neutralize the PH by adding something in ? eg HEPES?
You can try adding MOPS as buffer. Some RPMI 1640 comes with MOPS as buffer, others just rely on phosphate buffered system. I normally use 6.25 mM MOPS (final conc.) but have seen people use MOPS in final conc 165 mM.
You can also purchase RPMI 1640 with MOPS from USBiological or other company.
i used 10mM HEPES in joklik's medium to stabilize the pH;
But with DMEM, i just wait with the medium open under hood that color came back to acceptable color. you can enhance that by pipetting up and down the medium.
i usually start by preparing the media with genticin and leave it in the hood while I start with splitting cells or any other thing I am doing so that by the time I am ready to use the media, the pH has stabilised.