Figure 3. Photounbinding occurs for labeled, but not for unlabeled CaM.

A: Illuminated patch of CaM-A647 and CKII(290–312) by 633 nm laser light; laser power: 190 µW (flux  = 589 nJ/µm²), scale bar  = 10 µm. B: rebinding pattern (CaM-A488 fluorescence). C: illumination of unlabeled CaM and CKII(290–312) peptide by 488 nm laser light within the indicated patch (yellow dashed line); laser power: 370 µW (flux  = 1.15 µJ/µm²), green dots: fluorescent beads to allow proper focusing. D: no rebinding of A647 was observed after laser illumination within the corresponding patch.