Difference between SiRNA and shRNA - (May/26/2006 )

What is the diffenece between SiRNA and shRNA ?

siRNA is small interferance RNA, synthesized and applied directly on target. short term knockdown only

shRNA is short helical RNA, have to be cloned into a vector. the plasmids can be used for transfecting cells. Or made into virus (if viral vector) and could be used for long term knockdown.

siRNA : small iterfering RNA. Double strand RNA molecule, syntetized directly in vitro and annealed, with 3' overhangs or resulting from an invitro long RNA degradation by DICER.
This molecule is for transient knockdown, and may be delivered in cells by electroporation or lipid mediated transfection.

shRNA : short hairpin [si] RNA.
It's the long term application of siRNA. You have to clone a DNA molecule in an expression vector. The RNA molecule will fold in an hairpin, processed in the cell by dicer.
It's for short or lont term knock down of a protein in a cell or in vivo in a mouse for example.