Fig. 3.
Photochemical release of beads from cells of CR in microfluidic systems. (A) A cartoon depicting the photochemical cleavage of the beads from cells; the two fragments are a methyl ketone (3) and a primary amide (4). (B–M) A series of chronological images showing the photochemical release of a bead from a cell with two PS beads (3-μm diameter) attached. The cell was illuminated with UV light (λ = 365 nm, 80 W) for 20 sec before the image in frame 1 was acquired. The arrow in frame 1 indicates the direction in which the cell is rotating. The time that had elapsed between the frames was 2 sec. After 18 sec (J), the bead was released from the cell and slowly diffused away. We presume that this interval reflects the time for the initial photoproduct to cleave. The cell was imaged by using phase contrast microscopy. (Magnification: ×40.)