Hi, I am conducting an experiment on T cell killing. I have Pan CD3+ cells that I plan to activate, but I also keep a stock of resting T cells (not activated). What is the concentration that these resting T cells need to be in? The last batch that I maintained started dying within 10 days. I read that there is an optimal concentration to maintain these resting T cells. I believe the previous batch I maintained was at a diluted concentration (500,000 cells/mL), and that the concentration should have been higher (>2 x10^6 cells/mL). Is this correct? Thank you.