Line-scanning quasi-confocal fluorescence imaging

In order to overcome the drawbacks of traditional fluorescence imaging methods and to achieve a biochip fluorescence imaging technique with high sensitivity and low costs, a novel biochip fluorescence imaging technique, line-scanning quasi-confocal fluorescence imaging method, was proposed and a prototype system was set up. By using a line scanning to replace a point scanning and changing the 2-D scan into the 1-D scan, the system can provide higher sensing speeds, simpler structures and lower costs while maintaining the high sensitivity. To verify the feasibility of the method, the prototype system was used to sense the fluorescence image of a manually prepared low density DNA microarray. Experimental results indicate that the spatial resolution of the system is better than 18 μm, and the Signal to Noise Ratio(SNR) of the system is 5.5×102 by using the pixel-averaging method to reduce noises.By combining the low cost and simple structure of the area imaging method with the high sensitivity of the confocal point-scanning imaging method, the technique is suitable for the biochip study in laboratories.