As ensitive array fo rm icroRNA expression profiling (miChip) based on locke dn ucleic acids (LNA)

MicroRNAs represent ac lass of short ( ; 22 nt), noncoding regulatory RNAs involved in development, differentiation, and metabolism. We describe an ovel microarray platform for genome-wide profiling of mature miRNAs (miChip) using locked nucleic acid (LNA)-modified capture probes. The biophysical properties of LNA were exploited to design probe sets for uniform, high-affinity hybridizations yielding highly accurate signals able to discriminate between single nucleotide differences and, hence, between closely related miRNA family members. The superior detection sensitivity eliminates the need for RNA size selection and/or amplification. MiChip will greatly simplify miRNA expression profiling of biological and clinical samples.