Schematic of the perfusion circuit used in the imaging-flow experiments.

The components, numbered sequentially, are: (1) microscope objective, Nikon Plan Fluor 20 × 0.5NA; (2) and (3) motorized 4-position filter cube selector (computer controlled) with Nikon filter cubes; (4) Nikon tube lens; (5) horizontal microscope with a quartz illuminator; (6) and (7) Nikon epi-illuminator and 75 W xenon-arc lamp, which may optionally be connected via a liquid light guide; (8) vertically mounted flow chamber; (9), (10), and (11) manual microtranslators for x-y positioning and focusing of the specimen; (12) and (13) sample reservoir, connected to chamber with minimal length of tubing, and syringe pump operating in withdrawal mode.