Preparation and analysis of microRNA libraries using the Illumina massively parallel sequencing technology

MicroRNAs are key regulators of gene expression in diverse biological processes and their importance in embryonic stem cells is indisputable. New 'next-generation' technologies such as Illumina massively parallel sequencing offer vast improvements, in both scale and sensitivity, to microRNA profiling studies. We describe a detailed procedure for the preparation of small RNA libraries for Illumina sequencing. We further comment on approaches for analyzing the resultant sequence data for measuring microRNA abundance.