Patent ID: 7488603

Claim:
A method of extracting an analyte from a solution comprising the steps of: a. passing a solution containing an analyte back and forth through a pipette tip column, wherein the pipette tip column is comprised of: i. a column body having an open upper end, an open lower end, and an open channel between the upper and lower ends of the column body, ii. a bottom frit bonded to and extending across the open channel, iii. a top frit bonded to and extending across the open channel between the bottom frit and the open upper end of the column body, wherein the top frit, bottom frit, and column body define the extraction media chamber, wherein the top frit and the bottom frit are less than 350 microns thick, wherein the bottom frit is a membrane screen and the top frit is optionally a membrane screen, and wherein the membrane screen is selected from a group of materials consisting of nylon, polyester, polyamide, polycarbonate, cellulose, polyethylene, nitrocellulose, cellulose acetate, polypropylene, polysulfone, and glass, and iv. a bed of extraction media having a bed volume, whereby analyte adsorbs to said extraction media; and b. eluting the analyte by aspirating and discharging a desorption solvent through the pipette tip column, and wherein said analyte is an active protein.