miR-21 Plate Assay Kit

miR-21 is overexpressed in a wide variety of cancers. It is believed to be an oncogene by downregulating the expression of many tumor suppressors, including programmed cell death 4 (PDCD4), tumor suppressor Pdcd4, the PTEN tumor suppressor gene, and the tumor suppressor gene tropomyosin 1 (TPM1). miR-21 also found to be an important regulator of cancer-cell survival. Differently from the survival pathway mediated by IL-6/Stat3 activation through expression of antiapoptotic proteins, miR-21 is upregulated by Stat3, which mediates the suppression of apoptosis possibly through the inhibition of TPM1 and/or other proteins. Signosis’ miR-21 plate assay provides a simple and quick assay to analyze this miRNA molecule.

A. Benefits:

Signosis' miRNA plate arrays offer following benefits:

• Simple - Do miRNA detection as doing ELISA. It does not need enzymatic conversion from miRNA into cDNA. The entire assay procedure is “incubation and wash”.

• Higher sensitivity and better discrimination power - The detection is approximately 100 times more sensitive than miRNA Northern blot. In addition, it has higher discrimination power than miRNA Northern blot in differetiating miRNA isoforms.

• Quantitative comparison – The difference of two or more samples in the expression of a specific miRNA can be quantitatively analyzed.

B. Principle of the technology

In the proprietary miRNA plate assay, one miRNA molecule is flanked by a capture oligo and a biotinated detection oligo through two bridge oligos. One of the bridge oligos is partially hybridized with the miRNA molecule and the capture oligo and another one with the miRNA and the detection oligo. The hybrid is captured onto plate through hybridization with an immobilized oligo and detected by a streptavidin-HRP conjugate and chemiluminecscent substrate. This hybrid structure is sensitive to the sequence of the miRNA molecule. One nucleotide difference can prevent the formation of the hybrid and therefore miRNA isoform can be differentiated, which normally is hard to do with Northern blot. In addition, the sensitivity of the assay is higher than miRNA Northern blot assay.