siRNA / miRNA gene silencing Human ACC-MESO1

I would like to regulate the expression of a gene and in order to do that, I have purchased specific siRNA. After optimizing my transfection protocol and using electroporation I have achieved a 60-70% reduction of the gene of interest. However, I cannot observe a significant reduction of mRNA expression but only a reduction of protein. What might be the problem? Could the problem be in my cell treatment method?

Get tips on using B2M siRNA to perform siRNA / miRNA gene silencing Human - hES cell line H1 (WA01) B2M

Get tips on using N-WASP siRNA (h) to perform siRNA / miRNA gene silencing Human - T47-D N-WASP

Get tips on using VEGF-D siRNA (h) to perform siRNA / miRNA gene silencing Human - Caki-2 VEGF-D

Get tips on using EPAS-1 siRNA (h) to perform siRNA / miRNA gene silencing Human - HeLa EPAS-1 Lipid

Get tips on using IL-8 siRNA (h) to perform siRNA / miRNA gene silencing Human - HUVEC IL-8 Lipid

Get tips on using Glut1 siRNA and shRNA Plasmids (h) to perform siRNA / miRNA gene silencing Human - HT-1376 GLUT1

Get tips on using CD74 siRNA and shRNA Plasmids (h) to perform siRNA / miRNA gene silencing Human - HT-1376 CD74

Get tips on using siRNA ATX-1 or ENPP2 to perform siRNA / miRNA gene silencing Human - A2780 ATX-1

Get tips on using Pre-designed and validated siRNA against gene IGFBP1 to perform siRNA / miRNA gene silencing Human - Primary Endometrial Stromal Cells IGFBP1 (Insuline-like growth factor binding protein-1)