The Analysis on the Signals Denoising and Single Base Pair Resolution of DNA Sequencing

Capillary electrophoresis - Laser Induced fluorescence (CE - LIF) signals in DNA sequencing analysis are often contaminated by random noise, which has negative influence on the accuracy and detection limit of analysis. Wavelet analysis is a powerful tool for signal denoising comparing with other conventional denoising methods, but it needs more processing time in computer. Especially in some real-time embedded analysis system, it may increase hardware investment. Conventional denoising method such as Low-Pass filter, it can realize by cheap hardware, but its denoising quality is not very satisfactory. If we proper combined the low-pass and wavelet denoising method, it will enhance the denoising efficiency and lower the system´s cost. In our experiment, a novel method was presented: CE - LIF signals acquired from PMT were preprocessed by Butterworth low-pass filter in hardware circuit and the wavelet denoising was executed in computer. If we properly choose the cut-off frequency and wavelet denoising method, the denoising efficiency was high and the denoising quality was satisfactory. The denoising experiment results indicate that our denoising method can enhance the signal-to-noise ratio (SNR) and meet the requirement of single base pair resolution in DNA sequencing.