Confocal scanning fluorescence detection system and its optimization

ABSTRACT Fluorescence detection by confocal scanning systems has advantages of large area detection, small focus depth, largenumerical aperture, complete laser rejection, low background noise, high sensitivity and S/N ratio. It is a sensitive andprecise method to record and analysis results of biological or biomedical assay, such as DNA hybridization assay or microcapillary electrophoresis assay on biochip. Parameters like power of laser or sensitivity of PMT are responsible for signal tonoise ratio and sensitivity ofthe system, which should be optimized relative to different situations. The structural design andexperimental analysis on parameter optimization of a confocal scanning fluorescence detection system are presented in thispaper.Keywords: Confocal scanning fluorescence detection system, Biochip. 1.INTRODUCTION The first step ofHuman Genome Project was completed in 2000 so that whole sequences ofhuman genes were mapped. Buta heavy burden of work has still to be fulfilled about how genes express themselves and what the relationship will bebetween some kind of genes and a certain disease. Recently developing biochip technology has brought a revolution inbiological and medical fields which makes it possible that biochemical analysis takes place on a small chip automatically