pSilencer™ 4.1-CMV Expression Vectors These vectors feature a modified cytomegalovirus (CMV) promoter, a pol II promoter, for a high level of siRNA or miRNA expression in a wide variety of cell types and improved long-term gene silencing. pSilencer™ 5.1 Retro System These retroviral vectors enable long-term siRNA-mediated repression of gene expression in cell culture models, including difficult-to-transfect cell lines.pSilencer™ adeno 1.0-CMV System The advantages of adenoviral vectors combined with an efficient siRNA expression system.pSilencer™ siRNA Expression Vectors with Antibiotic Selectable Markers Select transfected cells using these vectors that confer antibiotic resistance in addition to expressing siRNAs.