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AssigneeCiba-Geigy Corporation
InventorsAndreas Manz, D. Jed Harrison, Carlo S. Effenhauser
Estimating the term…
In a method for controlling sample introduction in microcolumn separation techniques, more particularly in capillary electrophoresis (CE), where a sample is injected as a sample plug into a sampling device which comprises at least a channel for the electrolyte buffer and a supply and drain channel for the sample. The supply and drain channels discharge into the electolyte channel at respective supply and drain ports. The distance between the supply port and the drain port geometrically defines a sample volume. The injection of the sample plug into the electrolyte channel is accomplished electrokinetically by applying an electric field across the supply and drain channels for a time at least long enough that the sample component having the lowest electrophoretic mobility is contained within the geometrically defined volume. The supply and drain channels each are inclined to the electrolyte channel. Means are provided for electrokinetically injecting the sample into the sample volume. The resistance to flow of the source and drain channels with respect to the electrolyte buffer is at least about 5% lower than the respective resistance to flow of the electrolyte channel.
A method for controlling sample introduction in microcolumn separation techniques, in especially in capillary electrophoresis (CE), wherein an electrolyte buffer and a more or less concentrated sample are transported through a system of capillary channels, and wherein said sample consisting of components having different electrophoretic mobilities is injected as a sample plug into a sampling device, which comprises at least a channel for the electrolyte buffer and a supply and drain channel for said sample, said electrolyte channel and said supply and drain channels for said sample intersecting each other, and said supply and drain channels each being inclined to said electrolyte channel and discharging into it at respective supply and drain ports, wherein a distance between said supply port and said drain port geometrically defining a sample volume, characterized in that the injection of said sample plug into said electrolyte channel is accomplished electrokinetically by applying an electric field across said supply and drain channels for a time period which is at least long enough, that a slowest of said sample components having the lowest electrophoretic mobility is contained within said geometrically defined volume.
A method according to any one of the preceeding claims, wherein said system of capillary channels including said supply and drain channels with their respective ports are etched or micromachined or otherwise established in a planar substrate made of glass, or semiconductor materials, or a suitable polymer, or the like.
A sampling device comprising a channel for an electrolyte buffer and a supply channel and a drain channel for a sample, which each discharges into said electrolyte channel at a respective supply and a drain port, which ports are located with respect to each other such, that a sample volume is geometrically defined, said supply and drain channels each being inclined to a longitudinal extension of said channel piece, and means for electrokinetically injecting a sample into said sample volume, characterized in that said source channel and said drain channel, each have a resistance to flow with respect to said electrolyte buffer, which is about 5% lower than the respective resistance to flow of said electrolyte channel.
Dependencies are inferred from the claim text.