Patent ID: 7833398

Claim:
A method of separating molecules of varying length, the method comprising: (a) providing an apparatus that comprises a chamber having a first region and a second region, wherein the second region comprises one or more layers of membranes having pores, and a composition comprising molecules of varying lengths disposed in said chamber; (b) applying a predetermined driving force appropriate to drive specific length molecules from the first region entirely into the pores of second region, thereby entrapping the specific length molecules in the pores, and to drive molecules longer than the specific length from the first region partially into the pores of second region; (c) reducing or removing the driving force to cause molecules that are longer than the specific length molecules and that are not driven entirely into the pores of the second region during the application of the driving force to recoil back into the first region, and wherein the first region comprises a sufficiently lower free-energy than the second region such that the step of reducing or removing the driving force effects the recoil, and thereby separating the entrapped specific length molecules from the recoiled longer molecules.