MicroRNA Assay Range Grows

A wider range of new microRNA assays are based on a simple two-step process using stem-loop technology for reverse transcription (RT) of the mature microRNA that is followed by quantitative real-time polymerase chain reaction (PCR).

MicroRNA (miRNA) is a form of single-stranded RNA which is typically 20-25 nucleotides long, and is thought to regulate the expression of other genes. miRNAs are RNA genes that are transcribed from DNA but are not translated into protein. The DNA sequence that codes for an miRNA gene is longer than the miRNA.

Applied Biosystems (Warrington, UK) has expanded its range of TaqMan miRNA assays, now offering nearly 300 individual assays for cell differentiation, developmental biology, and stem cell and cancer research. In preliminary studies, the assays were able to quantify miRNAs in samples as small as 25 pg of total RNA and discriminate between highly homologous mature miRNAs, such as the hsa-let-7 family.

The specificity, combined with the sensitivity and range of TaqMan assay chemistry and real-time PCR, offers a robust, easily scalable, and cost-effective method to relate the expression of miRNAs with cell types. The assay will enable doctors to determine the original tissue type that gave rise to a cancer and to target treatment of the cancer. Already, miRNA profiling has been used to determine whether leukemia patients have slow-growing or aggressive cancer.

"We have been using the TaqMan microRNA assays to study different types of brain tumors,” said Prof. Victor Ambros of Dartmouth Medical School (Hanover, NH, USA), the original discoverer of miRNA molecules. "Our studies show these assays to be the most reliable and quantitative way to screen for microRNA biomarkers that distinguish tumor types.”



Related Links:
Applied Biosystems
Dartmouth Medical School