you can lyse your cells by directly adding RLT (Rneasy Mini Kit) oder Trizol on the cells in case they adhered. Otherwise harvest them, wash and lyse. I normally use Rneasy Mini Kit like James advised it.
Thanks a lot guys for your valuable answers, however I am asking about how I could harvest the cells and decant the media while they are suspended ? in adhered cells we decant the media and we put TRIzole and go on, but in suspension cells I don't know !
Thank you so much guys for your help, just wondering how you get a pellet when you do centrifuge for this type of cells. I did centrifuge them at 300g, yet no pellet, do I need more speed for that ?