The CAP-e assay is performed by allowing red blood cells (erythrocytes) to absorb antioxidants from a physiological liquid that contains a potential antioxidant product. All compounds that are not absorbed into the cells are then removed. The cells are exposed to oxidative stress. An indicator dye shows the degree of intracellular damage to the cell, in the presence versus absence of serial dilutions of the test product.
We specifically developed the CAP-e antioxidant test to help bridge the transition from chemical antioxidant assays (such as ORAC and total phenolics testing) to biological testing in more complex cellular systems. Our CAP-e White Paper explains the development of the CAP-e assay for bioavailable antioxidants and describes various applications in vitro and in vivo/ex vivo.