High-contrast imaging of moving targets

The imaging of cells flowing through blood vessels can be a useful diagnostic tool'. However, live samples are usually transparent and contrast is poor with bright-field microscopy. A variety of methods are available to improve contrast including; phase contrast, differential interference contrast, fluorescent labelling and surface plasmon resonance imaging. These methods are not all amenable to automated cell detection and analysis, however, because the cell is not easily separable from the background.