Putting the MicroRNA in MicroArray

Expression microarrays have enabled researchers to analyze the expression of hundreds of thousands of genes simultaneously to evaluate the global changes of a single perturbation. mRNA expression arrays were the first on the market. The mRNA to be hybridized to the array could be labeled directly or indirectly during reverse transcription using an oligo dT primer. Van Gelder et al improved the sensitivity by developing a way to amplify the target RNA using T7 RNA polymerase. Many improvements on this method have since increased the sensitivity further, such as those offered by the Enzo BioArray® Low Input RNA Amplification and Biotin Labeling System.

Recently the importance of microRNAs (miRNAs) in development and cell function has been realized. These small (~22 nt) non-coding RNAs with no polyA tail regulate gene expression, possibly by targeting mRNAs. Labeling miRNAs is not as straight forward as labeling mRNAs. Sun et al. and Esau et al. have used the BioArray® Terminal Labeling Kit to label cDNA copies of miRNA after purification of total RNA. cDNA copies of each miRNA were made using reverse transcriptase and random hexamer primer. The cDNA copies were then labeled with the BioArray® terminal labeling kit. Using their own miRNA microarray, Esau et al. demonstrated that miRNA-143 is important in regulating adipocyte differentiation. Sun et al. identified several miRNAs that are only expressed in specific tissue, such as kidney or muscle.

Enzo’s pioneering work in genomic analysis, coupled with an extensive patent estate and enabling platforms, have strategically positioned the company to play an important role in the rapidly growing fields of life sciences and molecular medicine.

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