Occasionally, a docking event can be observed between a red vesicle displaying DNA-lipid C and a green vesicle displaying the complement, C′. This is observed as a colocalization of the red and green false-colored spots, which then continue to diffuse randomly in tandem. This video was taken using a dual band excitation filter, splitting the emission onto two halves of a CCD, and recombining the red and green emission signals into a single image for each frame. This allows real time observation of both vesicles simultaneously.
"Kinetics of DNA-mediated Docking Reactions Between Vesicles Tethered To Supported Lipid Bilayers", Yee-Hung M. Chan, Peter Lenz, and Steven G. Boxer, PNAS, 104, 48, 18913-18918 (2007). [pdf]