Figure 7.

Intact, viable cells were necessary for MTT reduction. OD by lysate and supernatant of PC-3 cells compared to PC-3 cells (as positive control) and cell-free media (as negative control) following 3 hours of incubation with 0.4 mg/mL MTT. 20,000 cells were seeded per well of 96-well plates and were allowed to grow in phenol red-free FCS-containing RPMI for 24 h. The media was then replaced with fresh media of the same type with or without FCS. Two hours later, cells supernatant and lysates were isolated, and all samples had MTT added. Data shown as mean OD of triplicate wells and error bars represent SD (standard deviation). *** p-value < 0.0001.