Bare Morpholinos oligos, like all antisense molecules, need assistance to efficiently penetrate the plasma membrane of cultured eukaryotic cells. You will need some sort of delivery strategy to get the oligos into the cytosol. Options for Morpholino delivery include:

• Endo-Porter (our best delivery reagent, a peptide);
• Special Delivery (our previous delivery system, using ethoxylated polyethylenimine and Morpholino/DNA heteroduplexes);
• Scrape loading (a technique for adherent cells) or syringe loading (for suspension cells);
• Microinjection (this works great, but requires great patience for cell culture!);
• Electroporation (often used for chick embryos, works in cell cultures).

For delivering single-stranded Morpholino oligos into cultured cells, Gene Tools makes Endo-Porter delivery reagent and resells Sarstedt cell scrapers. Gene Tools also provides protocols for making Special Delivery heteroduplex oligos and provides EPEI delivery reagent to release the heteroduplexes from endosomes.