miRNA Microarray Profiling with Three Different Total RNA Prep Methods

We performed miRNA microarray profiling on samples prepared from two different cell lines by three widely-used total RNA sample prep methods. miRNA microarrays were manufactured by Agilent Technologies (Santa Clara, CA), and contain 20-40 features targeting each of 470 human miRNAs (Agilent design ID 016436). Sequences of the 470 miRNAs were obtained from the Sanger miRBase, release 9.1. Labeling and hybridization of total RNA samples were performed according to the manufacturer’s protocol. 100ng total RNA was used as input into the labeling reaction, and the entire reaction was hybridized to the array for 20 hours at 55°C. For total RNA preps, frozen cell pellets were resuspended in phosphate buffered saline and divided into equal aliquots of 5x106 (HeLa) or 1x107 (ZR-75-1) cells and refrozen. Individual aliquots were subsequently thawed just before use.