following a 1-h exposure to am2 , a dose of drug required to give 50 % loss of cell viability ( 53 microm ) was obtained in the dark , which was reduced to approximately 2.4 microm following illumination for 2 min ( lambda greater than 475 nm ) , a dose of light that was completely nontoxic to the cells in the absence of drug .
C0007620
cell viability
C0007634
cells