Confocal fluorescence detection microchip

Fig. 3 Confocal fluorescence detection on a microchip. A laser was used as the excitation source. The laser light passed through a biconvex lens, was focused into an illumination pinhole, and was subsequently reflected by a dichroic mirror and focused in the channel on the capillary electrophoresis (CE) chip by a microscope objective. The fluorescence signal from the sample, collected by the microscope objective, was passed through the dichroic mirror, focused by the tube lens into a confocal pinhole, and then detected by a photomultiplier tube (PMT). To improve the signal-to-noise ratio, band-pass filter and notch filter were inserted above PMT for spectral filtering...

Dang, F, Zhang, F., Hagiwara, H., Mishina, Y. and Baba, Y. Ultrafast analysis of oligosaccharides on microchip with light-emitting diode confocal fluorescence detection. Electrophoresis, 24, 714, 2003. 

FIGURE 7.3 The rotary confocal fluorescence scanner used to detect pCAE chip separations. Laser excitation at 488 nm (100 mW) is directed up through the hollow shaft of a computer-controlled stepper motor, deflected 1.0 cm off-axis by a rhomb prism, and focused on the electrophoresis lanes by a microscope objective. The stepper motor rotates the rhomb/objective assembly just under the lower surface of the microchip at five revo-lutions/s. Fluorescence is collected along the same path and spectrally, and is spatially filtered before impinging on the four-color confocal detector [980]. Reprinted with permission from the American Chemical Society. 

Jiang, G., Attiya, S., Ocvirk, G., Lee, W.E., Harrison, D.J., Red diode laser induced fluorescence detection with a confocal microscope on a microchip for capillary electrophoresis. Biosens. Bioelectronics 2000, 14, 861-869. 

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