microRNA Detection by Membrane based DNA Array• Based on proprietary T7-OLA (oligo ligation assay) amplification technology
• High discriminative power - It is able to differentiate all miRNA isoforms. All let7 isoforms can be clearly distinguished in the assay
• Linear amplification - Captured miRNAs are subjected to T7 amplification without introduction of bias in PCR
• No pre-isolation of miRNA - Total RNA (as low as 0.5 ug) can be directly used for the assay without pre-isolation of miRNA
• Simple procedure – The assay is simple and straightforward
MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate up to 30% of mammalian gene expression. So far, more than 400 miRNAs have been identified in the human genome and many of them are only different in one or a few nucleotides. Expression of mature miRNAs is tissue-specific and the abundancy of miRNAs varies in several orders of magnitude. Aberrant expression of miRNAs may be involved in human cancers.
miRNA is different from large messenger RNA in three aspects: (1) miRNAs are small size molecules with quite a big difference in abundance, (2) mature miRNAs co-exist with their precursor pre-miRNA and pri-miRNA, which only differ in length, and (3) many miRNAs are very closely related in sequences, such as isoforms, with the difference of only one or a few nucleotides.
Therefore, the conventional mircoarray technologies cannot directly be applied to analyzing these molecules. A number of miRNA microarray products are commercially available, but they are either tedious in requiring pre-isolation of microRNA, lack the discriminative power to differentiate isoforms, or are not sensitive enough to monitor low abundant miRNAs.
Principle of the Technology
In the Signosis miRNA array assay, each miRNA molecule is targeted by two oligos that hybridizes with the target miRNA to form an RNA/DNA duplex. When the sequences are perfectly matched, these are aligned with the miRNA and the joint can be ligated by DNA ligase, see figure below. A single nucleotide difference among miRNAs will block either the hybridization or the ligation, so that miRNA isoforms can be differentiated. Due to the small size of miRNAl, the hybrid might not be stable; here we introduce the stacking sequences. By extending these two oligos along with their complementary oligos the stability is increased. Once the pair of oligos is ligated, the ligated molecules are subjected to linear amplification via T7 transcription into RNA in the presence of biotin-UTP, which are used as probes for array hybridization. To differentiate each isoform, we assigned unique tag sequences to the ligation oligos, so that single nucleotide differences are converted into unique tag sequences. Therefore, each isoform can be easily distinguished by array hybridization.
Kannan, M. et al. (2009) Membrane array–based differential profiling of platelets during storage for 52 miRNAs associated with apoptosis. Transfusion 49: 1443-1450.
Wu, J. et al. (2011) HMGA2 Overexpression-Induced Ovarian Surface Epithelial Transformation Is Mediated Through Regulation of EMT Genes. Cancer Res 71:349-359
Farraj, A. et al. (2011) ST Depression, Arrhythmia, Vagal Dominance, and Reduced Cardiac MicroRNA in Particulate-exposed Rats. Am. J. Respir. 44: 185-196
|Human miRNA Array I||AP-0001-SO||3 rxns||722 €||DETAILS||Add to Cart|
|Human miRNA Array II||AP-0002-SO||3 rxns||830 €||DETAILS||Add to Cart|
|Human miRNA Array III||AP-0008-SO||3 rxns||939 €||DETAILS||Add to Cart|
|Human miRNA Array IV||AP-0009-SO||3 rxns||830 €||DETAILS||Add to Cart|
|Stem Cell (Human, Mouse, Rat) miRNA Array||AP-0007-SO||3 rxns||830 €||DETAILS||Add to Cart|
|Cancer miRNA Array||AP-0003-SO||3 rxns||939 €||DETAILS||Add to Cart|
|Human Apoptosis-Associated miRNA Array||AP-0004-SO||3 rxns||722 €||DETAILS||Add to Cart|
|Mouse miRNA Array||AP-0005-SO||3 rxns||939 €||DETAILS||Add to Cart|
|Rat miRNA Array||AP-0006-SO||3 rxns||939 €||DETAILS||Add to Cart|