As for my 12Z cell line, the cells grow very well and are tenacious to the wall of the plastic culture flasks. However, they do not adhere to the wells of plates properly after seeding the cells for experiments. I am currently conducting a scratch/wound healing assay with the 12Z cells and my drug treatments. Once I injure/scratch the full monolayer with a pipette tip, the adhered cells begin to lift off and the monolayer peels off completely instantly prior to treatments. At first, I thought the pH of my testing medium was too alkaline, but HEPES was already added into the medium and the pH was deemed to be normal. I am unsure as to why the 12Z cells do not adhere well outside of the culture flask.