B cell line - cell colour change and visible cell death - (Jun/06/2014 )

Hi there,

I am working with an EBV-immortalized human B lymphoblast cell line, it has been perfectly fine up until last week when the cells started turning an orangy-red colour, I have been working with this specific cell line for a year now and have never come across anything like this. The media we are using expired 2 months ago, could this be affecting the cells? I have also thawed a fresh vial which was fine up until yesterday and they have become showing the same colour change. 

Thank you

If the medium contains L-glutamine, it decomposes to an acidic compound, but this wouldn't alter the pH much, certainly not visibly. It is more likely that you have a bacterial or fungal (yeast) contamination.