Two days ago, we thawed Wharton's jelly human mesenchymal stem cells in the following media composition: DMEM-low glucose + 2 U/mL Heparin + 5% HPL + 1% antibiotic antimycotic + 2% HEPES. Attached is the picture of cells in P5. Today, we changed the media using the complete media that we already prepared two days ago. We took out the media from 4 degree Celsius and warmed it in a water bath. After changing the media, cells morphology changed (please refer "wj after changing media"). This happened after 30 minutes to 1 hour after changing media. Do we need to freshly prepare the media every time we want to use it?