miRNA transfection using oligofectamine (Invitrogen) Day 1 : Plate 100 000 HeLa cells per well (6-well plate) Day 2 : Per well 2 µl oligofectamine + 13 µl OPTIMEM 1.7 µl miRNA (20µM solution) + 183.3 µl OPTIMEM Mix Incubate 15 min. @ room temperature In the meantime, wash cells with pre-warmed OPTIMEM once. Add 800 µl OPTIMEM per well. Add the miRNA/oligofectamine mix. Leave 4 hours @ 37°C Add 1 mL complete DMEM. Leave cells overnight Day 3 : Retransfect cells as decribed before Add 1 mL complete DMEM. Leave cells 48h Day 5 : Harvest cells.