miR-ID® microRNA detection platform

The miR-ID® assays from SomaGenics enable sensitive and highly specific quantification of low abundance small RNAs, such as microRNAs, from total RNA isolates. This novel platform uses a circularisation-based real time quantitative PCR (qPCR) method for quantifying microRNAs (miRNAs) and related isomiRs and isoforms. This technology is compatible with all sample sources, including total RNA, cell lysates and tissue lysates.

Benefits of using the miR-ID® microRNA detection platform
• Ideal for absolute or relative miRNA quantification
• Distinguish 2’Omethyl modifications at the 3’-terminus of miRNAs
• Compatible with all sample sources including total RNA, cell lysates and tissue lysates

miR-ID® technology

Step 1: Circularisation of a linear miRNA; Step 2: Reverse transcription mediated by rolling circle amplification to obtain multimeric cDNA; Step3: Quantification of the amplicon by RT-qPCR using highly sequence-specific 5’-overlapping primers and SYBR Green detection.

miR-Direct® workflow

All steps up to quantitative PCR are performed in multiplex in a single tube. Note that this schematic includes the miR-ID® steps.

miR-ID® is highly sensitive and specific

For example, the closely related miRNAs 34a, b, and c are well discriminated by miR-ID®. To determine the relative Ct values listed in the table, the difference in Ct values for the intended target and their related isoforms was converted into a linear percentage, with the fully matched reaction normalised to 100%. All non-specific detection is well below 1% for these assays. The dilution curves indicate that all three assays have a dynamic detection range of 8 logs.

miR-ID® detects end-modified small RNAs

miR-ID® quantitatively discriminates between small RNAs with an identical sequence but differing terminal modifications. This is particularly useful in plant miRNAs, where discrimination between 2-O-methyl modified and unmodified miRNA is of considerable interest.

miR-ID® can quantitatively detect 2' O-methyl modifications at the 3’-terminus of miRNAs. By selecting enzymes that circularize either both types of miRNAs (with 2’-OMe or 2’-OH forms on the 3’termini), shown in green, or 2’-OH forms only (shown in red), these two end-modifications can be distinguished. In this example, synthetic let-7b miRNAs with the two respective 3’ termini were assayed and quantification with the enzyme circularizing both forms were set to 100%

Material available for download
miR-ID® miRNA quantification assays protocol
miR-ID® brochure
miR-ID®: a sensitive and specific method for microRNA quantification
Paper: miR-ID: A novel, circularization-based platform for detection of microRNAs

New miR-ID® assays are continually being added. If you do not see your miRNA on our list or are interested in detecting novel isoforms, please contact us as it may be available shortly or by special order.