限制性显示技术作为一种高密度长链寡核苷酸芯片样本标记方法的初步研究

目的 初步研究限制性显示技术(RD-PCR)作为一种高密度长链寡核苷酸芯片样本标记方法对芯片杂交信号的影响。方法 收集3个健康人外周血单核细胞,提取RNA后分为两组,采用RD-PCR进行样本双色(Cy3/Cy5)荧光标记,与3张Agilent60mer高密度(22K)人1B寡核苷酸芯片进行杂交。排除阴性和阳性对照信号值、Cy3和(或)Cy5的前景与背景间无统计显著性差异点的信号值,进一步排除两种荧光标记间存在统计显著性差异点的信号值,将3张芯片的共同信号值用于分析。SPSS软件进行常规统计分析和作图,R语言环境下的VSN统计包排除芯片间和两种不同荧光标记间的系统误差。结果 3张芯片的8744个共同点用于本研究。芯片间及两种荧光标记间存在明显的可校正的系统误差。芯片间杂交信号值相关显著。RD-PCR样本标记方法对较低表达基因信号值较为敏感。结论 初步的统计分析结果表明,RD-PCR是一种潜在的有用的高密度长链寡核苷酸芯片样本标记方法。

A novel sample labeling method with restriction display PCR for 60-mer oligonucleotide microarray

Objective To investigate the value of restriction display PCR (RD-PCR) as a novel and expedient sample labeling method for high-density 60-mer oligonucleotide microarray. Methods Peripheral blood samples from three volunteers were collected and the total RNA was extracted from the peripheral blood mononuclear cells and labeled with RD-PCR protocol, followed by hybridization with Agilent Human 1B oligonucleotide microarrays in a two-color comparison format. The RNA from the same subject was divided into two aliquot and labeled with Cy3 and Cy5 respectively. The spots with significant difference between the foreground and local background intensities and those without significant difference between Cy5 and Cy3 signal intensities were selected for analysis. SPSS software was used to perform the statistical tests and plot generation. VSN packages were used under R language to remove the systematic array and dye biases. Results Totally 8744 common spots of the 3 microarrays were evaluated. The results demonstrated that RD-PCR could be a promising novel method for efficient labeling of microarray samples. Further analysis indicated the presence of adjustable biases derived from the array and incorporated dye in the labeling processes. The RD-PCR labeling showed better performance than the conventional approaches in regards to reproducibility of the quantitative signals for gene intensity and capability to label RNAs of lowly expressed genes. Conclusion Given the evidence of the feasibility of using RD-PCR labeling in the field of high-density long oligonucleotide microarray, further optimization of the protocol may unleash the full potential of this novel labeling method.