doi:10.1093/nar/gkn932 Quality Assessment and Data Analysis for microRNA Expression Arrays

MicroRNAs are small (~22nt) RNAs that regulate gene expression and play important roles in both normal and disease physiology. The use of microar-rays for global characterization of microRNA expres-sion is becoming increasingly popular and has the potential to be a widely used and valuable research tool. However, microarray profiling of microRNA expression raises a number of data analytic chal-lenges that must be addressed in order to obtain reliable results. We introduce here a universal refer-ence microRNA reagent set as well as a series of nonhuman spiked-in synthetic microRNA controls, and demonstrate their use for quality control and between-array normalization of microRNA expres-sion data. We also introduce diagnostic plots designed to assess and compare various normaliza-tion methods. We anticipate that the reagents and analytic approach presented here will be useful for improving the reliability of microRNA microarray experiments