Patent ID: 8252527

Claim:
A method for identifying a test polynucleotide that can reduce the level of a target mRNA comprising the steps of: i) providing cells expressing an RNA polynucleotide comprising a target mRNA sequence, a single internal ribosome entry sequence (IRES) and a sequence encoding a secreted reporter protein, wherein the single IRES is 3′ to the target mRNA sequence and 5′ to the sequence encoding the secreted reporter protein; ii) introducing to the cell a test polynucleotide, and iii) measuring activity of the secreted reporter protein; wherein a reduction in secreted reporter protein activity relative to a control cell expressing an RNA polynucleotide comprising the target mRNA sequence, the single IRES and the sequence encoding the secreted reporter protein into which the test polynucleotide has not been introduced is indicative that the test polynucleotide is capable of reducing the level of the target mRNA in the cells.