Ambion has recently introduced Pre-miR miRNA precursor molecules.

The molecules are chemically modified and optimized nucleic acids designed to mimic the microRNA molecules in cells, the company said. They are designed to directly enter into the miRNA processing pathway, and "are treated identically to endogenous miRNA within the cell. Since the … molecules directly enter the miRNA pathway, they eliminate any non-miRNA cellular response that is seen with siRNA-like designs."