Abstract: The present invention provides methods of post-transcriptional gene silencing which involve the use of a first dsRNA having substantial sequence identity to a target nucleic acid and a short, second dsRNA which inhibits dsRNA-mediated toxicity. These methods can be used to prevent or treat a disease or infection by silencing a gene associated with the disease or infection. The invention also provides methods for identifying nucleic acid sequences that modulate a detectable phenotype, including the function of a cell, the expression of a gene, or the biological activity of a target polypeptide.

Abstract: The invention features methods of analyzing the kinetics properties of transfection reactions. Also featured are methods for creating structural promoters which are effectively unregulated by enhancers and repressors. The structural promoters are significantly more active than the native promoter sequences upon which they are based.

Abstract: Conserved consensus sequences from known hepatitis B virus strains and known hepatitis C virus strains, which are useful in inhibiting the expression of the viruses in mammalian cells, are provided. These sequences are useful to silence the genes of HBV and HCV, thereby providing therapeutic utility against HBV and HCV viral infection in humans.

Abstract: The present invention provides methods of post-transcriptional gene silencing which involve the use of a first dsRNA having substantial sequence identity to a target nucleic acid and a short, second dsRNA which inhibits dsRNA-mediated toxicity. These methods can be used to prevent or treat a disease or infection by silencing a gene associated with the disease or infection. The invention also provides methods for identifying nucleic acid sequences that modulate a detectable phenotype, including the function of a cell, the expression of a gene, or the biological activity of a target polypeptide.