Abstract: The invention relates to a composition, solution, and method for delivering desired substances into the cytosol of living eucaryotic cells. The composition includes a poly(ethylene glycol) component having a designated molecular weight in the range between about 300 and about 900 daltons, and a carbohydrate component which is membrane impermeable and water soluble. The osmotic delivery solution delivers reporter-tagged molecules and complexes, drugs, antisense and antigene oligos, RNAs, DNAs, peptides, proteins, carbohydrates, and the like into cultured cells using an improved osmotic delivery method. The method may also be used for extracorporal therapy. In a particularly preferred embodiment of extracorporal therapy, the desired substance delivered into the cytosol of the cells is a Morpholino antisense oligo.