The effect of replication on gene expression microarray experiments

<p>MOTIVATION:<br> We examine the effect of replication on the detection of apparently differentially expressed genes in gene expression microarray experiments. Our analysis is based on a random sampling approach using real data sets from 16 published studies. We consider both the ability to find genes that meet particular statistical criteria as well as the stability of the results in the face of changing levels of replication.<p> <p>RESULTS:<br> While dependent on the data source, our findings suggest that stable results are typically not obtained until at least five biological replicates have been used. Conversely, for most studies, 10-15 replicates yield results that are quite stable, and there is less improvement in stability as the number of replicates is further increased. Our methods will be of use in evaluating existing data sets and in helping to design new studies.<p>

<p>研究背景：<br>我们探讨了重复实验对基因表达微阵列实验中差异表达基因（differentially expressed genes）检测的影响。本分析基于随机抽样方法，使用来自16项已发表研究的真实数据集。我们既考察了找到符合特定统计标准基因的能力，也评估了不同重复水平下结果的稳定性。</p><p>研究结果：<br>尽管结果取决于数据源，但我们的发现表明，通常需要至少5次生物学重复（biological replicates）才能获得稳定结果。相反，对于大多数研究而言，10-15次重复实验可产生相当稳定的结果，且随着重复次数进一步增加，稳定性提升幅度减小。我们的方法可用于评估现有数据集，并帮助设计新研究。</p>