Gene and oligonucleotides transfection methods to the kidney are required for the progress of biomedical research and the therapy of renal diseases. In this study, we found that siRNA as well as plasmid DNA can be transfected to the kidney by a simple method including lightly and once pressing the kidney after intravenous injection of siRNA or plasmid DNA (renal press-mediated transfection method). Using luciferase as the reporter, gene expression and silencing properties were evaluated. Plasmid DNA is efficiently and widely transfected to the periphery of the pressed kidney, and also siRNA is transfected into the kidney and significant suppression of gene expression can be achieved. Additively, serum creatinine and blood urea nitrogen levels, that are indices of renal function, exhibited no marked changes after transfection by this method. Therefore, it appears that plasmid DNA and siRNA could be transfected to the kidney without renal dysfunction by renal press-mediated transfection method. (C) 2008 Elsevier Inc. All rights reserved.