Research On Fluorescence Detection System For Quantitative PCR Instruments

The development of polymerase chain reaction (PCR) used to amplify a target DNA sequence is a great breakthrough of genetic and makes a revolution to biomedical field. The quantitative PCR instrument makes use of the accumulated signal of fluorescence to monitor the whole process of PCR in real time and quantifies unknown target molecules by standard curve. It plays a very important role in pharmacy development, medical examination and gene identification. As core component of quantitative PCR instrument, the fluorescence detection system is used for detecting and processing weak fluorescence and changing. The accuracy of quantification largely depends on the performance of fluorescence detection systemThe principle and characteristics of fluorescence as well as the principle of quantitative PCR were studied in this paper. A compact structure and high optical efficiency fluorescence detection system was designed and established based on the analysis of fluorescent dye's spectrum and fluorescence detection methods. The system realized to detect and process four different fluorescence excitated by one high-power LED. Moreover, several experiments were carried out and testified that the system can avoided stray light effectively and detector extra weak fluorescence. Besides the system had low noise, high gain, wide frequency response and good anti-jamming performance. The performance of the system can satisfy the needs of quantitative PCR application. Advices to improve the performance of this system and plans of future work were given at the end of this paper.