DNA测序电泳荧光信号的小波去噪分析

Analyzing the wavelet denoising of electrophoresis fluorescence signals for DNA sequencing

在DNA荧光测序中,噪声影响分析的准确度和检出限。相比其他滤波方法,小波分析具有良好的时频域分辨特性。在小波去噪处理中,正确选择合适的小波基函数和去噪阈值直接关系到信号去噪处理的质量。通过对毛细管电泳(CE)荧光信号的仿真分析,结果表明:选择sym7小波基函数、分解层数(lev=5)与使用软阈值,可以有效去除CE荧光光谱信号的噪声,提高分析准确度。将其用于处理实际的DNA电泳荧光信号,效果良好。

Fluorescence signals in DNA sequencing are often contaminated by noise, which has negative influence on the accuracy and detection limit of analysis. Wavelet analysis has excellent time and frequency domain resolution for signal denoising comparing with other filtering methods. Before the signals denoising process, a key problem is how to choose a suitable wavelet base and denoising threshold, which have great influences on the quality of signals denoising. Through the simulation analysis of capillary electrophoresis （CE） fluorescence signals, the results indicate that using sym7 wavelet base, decomposition level at 5 and using soft threshold can effectively reduce the noise of CE fluorescence signals and enhance the accuracy of analysis. When it is applied to DNA CE experimental signal, the results are also satisfactory.