Abstract: The invention provides, inter alia, methods of extracting an analyte from a solution comprising the steps of: passing a solution containing an analyte through an extraction channel having a solid phase extraction surface, whereby analyte adsorbs to the extraction surface of said extraction channel; purging bulk liquid from said extraction channel; and eluting the analyte by passing a desorption solvent through the channel. The invention further provides reagents, columns and instrumentation related to this and other methods.

Abstract: The invention provides, inter alia, methods of extracting an analyte from a solution comprising the steps of: passing a solution containing an analyte through an extraction channel having a solid phase extraction surface, whereby analyte adsorbs to the extraction surface of said extraction channel; and eluting the analyte by passing a desorption solution through the channel, wherein the method includes a step wherein a multiple-pass solution is passed through at least some substantial portion of the extraction channel at least twice. Non-limiting examples multiple-pass solutions include a solution containing an analyte, a wash solution and/or a desorption solution.

Abstract: The invention provides extraction columns for the purification of an analyte (e.g., a biological macromolecule, such as a peptide, protein or nucleic acid) from a sample solution, as well as methods for making and using such columns. The columns typically include a bed of extraction media positioned in the column between two frits. In some embodiments, the extraction columns employ modified pipette tips as column bodies. In some embodiments, the invention provides columns characterized by low backpressure.

Abstract: The invention provides extraction columns for the purification of an analyte (e.g., a biological macromolecule, such as a peptide, protein or nucleic acid) from a sample solution, as well as methods for making and using such columns. The columns typically include a bed of extraction media positioned in the column between two frits. In some embodiments, the extraction columns employ modified pipette tips as column bodies. In some embodiments, the method involves adjusting the head pressure of the column during the process, or otherwise controlling or regulating the head pressure.