Low transfection of siRNA into HaCaT cells. Please help - (Aug/12/2006 )

Hi,
Could anybody help me please?
I'm trying to silence gene expression by a double stranded oligomer RNA (siRNA) on HaCaT cell line but transfection efficiency is very low. The transfection reagent I'm using is "Simporter" from "Upstate". If anyone uses another transfection reagent that works on HaCaT, please tell me.

Thank you in advence
Ella

Positional effects of short interfering RNAs targeting the human coagulation trigger Tissue Factor
T Holen, M Amarzguioui, MT Wiiger, E Babaie, H … -
Nucleic Acids Research, 2002
... 30, No. 8 1757-1766