There are several papers that have adapted Apak R. et al's (2007) method for assessing TAC in food homogenates to assess TAC in cell culture, but these papers' method sections are not descriptive enough. I am unsure if the assay is performed by lysing the cells and re-suspending them into a suspension or if the assay can be performed directly on intact cells attached to a plate. My understanding is that TAC is a measurement of the total capacity of intracellular enzymes to mitigate oxidative stress (by either lowering the production of ROS or scavenging for ROS). Any advice/recommendations on this would be appreciated!