One of the reasons pluripotent stem cells are so popular in medical research is that they can be differentiated into any cell type. However, typical differentiation protocols lead to a heterogeneous population from which the desired type must be purified. Normally, antibodies that react to surface receptors unique to the desired cell are used for this purpose. However, in many cases, the purification levels remain poor and the cells can be damaged. New RNA technology produced at the Center for iPS Cell Research and Application (CiRA) at Kyoto University in Japan may avoid these problems. Professor Hirohide Saito, at the Department of Reprogramming Science, is a bioengineer who makes tools for researchers working with induced pluripotent stem cells (iPSCs). His latest technology, the microRNA (miRNA) switch, is designed to detect and sort live cells not by surface receptors, but by miRNAs. miRNA is a better marker of cell types and can therefore improve purity levels. The advance was reported online on May 21, 2015 in the journal Cell Stem Cell. The article is titled “Efficient Detection and Purification of Cell Populations Using Synthetic MicroRNA Switches." Dr. Saito’s miRNA switches consist of synthetic mRNA sequences that include a recognition sequence for miRNA and an open reading frame (ORF) that codes for a desired gene, such as a regulatory protein, that emits fluorescence or promotes cell death. If the miRNA recognition sequence binds to miRNA expressed in the desired cells, the expression of the regulatory protein is suppressed, thus distinguishing the cell type from others that do not contain the miRNA and express the protein. Senior Lecturer Dr.Login Or Register To Read Full Story