Patent ID: 8148169

Claim:
An automated parallel method for passing liquid through a plurality of pipette tip columns comprising the steps of: a) providing a plurality of pipette tip columns, wherein each column is comprised of: i. a column body having an open upper end for communication with a pump, a first open lower end for the uptake and dispensing of fluid, and an open passageway between the upper and lower ends of the column body, ii. a bottom frit, wherein the bottom frit is at or near the open lower end of the pipette tip column, iii. an optional top frit positioned between the bottom frit and the open upper end of the column body, iv. a bed of hydrated gel resin media, v. a storage liquid, wherein the storage liquid is comprised of a water miscible solvent having a viscosity greater than that of water, and vi. a pump sealingly attached to the open upper end of the column, wherein the pump is comprised of a piston, and wherein actuation of the pump piston causes liquid to be drawn into or expelled from the bed of hydrated gel resin media; b) contacting said open lower ends of the columns with a liquid; c) actuating the pump piston to draw the liquid into the open lower ends of the columns and through the bed of hydrated gel resin media, wherein the volume of liquid drawn into the columns is 250 μl or less and wherein the pump piston displacement is 20 to 75 μl greater than the volume of liquid drawn into the column; and d) actuating the pump piston to expel the liquid through the bed of hydrated gel resin media and out of the open lower end of the columns.