P 1985 (OTTO) Poly(ethylene glycol) 4000 Cas 25322-68-3 - used in gene delivery of protoplast transfection and incubation. P 1985 (OTTO) Poly(ethylene glycol) 4000 Cas 25322-68-3 - used in the preparation of extraction for measuring cytosolic phosphoenolpyruvate carboxykinase (PEPCK) from plant tissues. It is useful to mediate DNA transformation into protoplasts derived from rice leaf sheat