Figure 4 of Viiri, Mol Vis 2009; 15:1799-1805.

Figure 4. Photoisomerization of UCA. UV excitation of one isomer leads to the formation of the other isomer (A). The concentrations of UCA isomers is measured in the cell culture medium of HCE-2 cells (B) and HCECs (C) treated with 100 µg/ml cis-UCA for 24 h with or without UV irradiation.