SEARCH Articles Figures Tables Conjugation of cell-penetrating peptides facilitates siRNA-mediated p38 MAP kinase silencing without transfection reagents. L929 cells were incubated for 24 h with siRNA in the absence of Lipofectamine-2000. p38 MAP kinase mRNA levels were determined using RT-PCR and normalized to 18s . Adopted from Bioconiueate Chemistry 2007 18 [Publishers Imprint]