HuSH-29 shRNA constructs for gene specific knock down provide long, 29-mer duplexes, which offer high potency, less off-target effect and reduced interferon induction. The product line covers every human gene locus. Four constructs are provided for each target gene at different regions for optimal inhibition. Puromycin selectable marker facilitates stable cell line production. The constructs can be used as a plasmid or packaged into a retrovirus for better delivery.