Abstract: Apparatuses and methods for whole column imaging detection (WCID) capillary isoelectric focusing (CIEF). The apparatus includes a separation capillary having a separation inner diameter and a separation outer diameter; a base, wherein the separation capillary is anchored to the base; an inlet transfer capillary having an inlet inner diameter and an inlet outer diameter; and an outlet transfer capillary having an outlet inner diameter and an outlet outer diameter. The inlet transfer capillary, the separation capillary, and outlet transfer capillary are configured to be in fluidic communication with each other. The separation inner diameter exceeds the outlet inner diameter.

Abstract: A method and apparatus are provided for performing capillary isoelectric focusing followed by mobilization of the focused zones by induced hydrodynamic flow or chemical mobilization. These two dimensions of separation are integrated with real-time whole-channel electrophoresis detection and automatic sample injection to achieve a separation resolution superior to that obtainable using known orthogonal capillary two dimensional arrangements.

Abstract: Apparatuses and methods for whole column imaging detection (WCID) capillary isoelectric focusing (CIEF). The apparatus includes a separation capillary having a separation inner diameter and a separation outer diameter; a base, wherein the separation capillary is anchored to the base; an inlet transfer capillary having an inlet inner diameter and an inlet outer diameter; and an outlet transfer capillary having an outlet inner diameter and an outlet outer diameter. The inlet transfer capillary, the separation capillary, and outlet transfer capillary are configured to be in fluidic communication with each other. The separation inner diameter exceeds the outlet inner diameter.

Abstract: An apparatus and method are disclosed for the precise selection and extraction of a selected analyte in a focused zone produced by isoelectric focusing performed in micro-channels. A cross-channel microfluidic device comprises a sample mixture introduction and separation channel and an extraction channel, which are in fluid communication with each other at a point of intersection. Means are provided for selectively moving the pattern of separated zones following cIEF to the intersection point, and means are provided for applying an extraction pressure to direct a single zone containing a selected analyte into and then out of the extraction channel for collection.

Abstract: An apparatus and method are disclosed for the precise selection and extraction of a selected analyte in a focused zone produced by isoelectric focusing performed in micro-channels. A cross-channel microfluidic device comprises a sample mixture introduction and separation channel and an extraction channel, which are in fluid communication with each other at a point of intersection. Means are provided for selectively moving the pattern of separated zones following cIEF to the intersection point, and means are provided for applying an extraction pressure to direct a single zone containing a selected analyte into and then out of the extraction channel for collection.

Abstract: A method and apparatus are provided for performing capillary isoelectric focusing followed by mobilization of the focused zones by induced hydrodynamic flow or chemical mobilization. These two dimensions of separation are integrated with real-time whole-channel electrophoresis detection and automatic sample injection to achieve a separation resolution superior to that obtainable using known orthogonal capillary two dimensional arrangements.

Abstract: An apparatus and method are disclosed for the precise selection and extraction of a selected analyte in a focused zone produced by isoelectric focusing performed in micro-channels. A cross-channel microfluidic device comprises a sample mixture introduction and separation channel and an extraction channel, which are in fluid communication with each other at a point of intersection. Means are provided for selectively moving the pattern of separated zones following cIEF to the intersection point, and means are provided for applying an extraction pressure to direct a single zone containing a selected analyte into and then out of the extraction channel for collection.

Abstract: Improved apparatus is disclosed for carrying out axially illuminated laser induced fluorescence whole-column imaging detection in the capillary isoelectric focusing of proteins. The separation capillary was made of low refractive index Teflon conditioned with methylcellulose to reduce electroosmotic flow and a small amount of high refractive index organic solvent (glycerol) was added to the sample mixture. It was found that an axially directed laser excitation beam was propagated essentially with total internal reflection, so that minimum interference arose from stray light or from scattering light originating from the wall of the capillary. With the naturally fluorescent protein R-phycoerythrin, a concentration detection limit LOD 10?11 M or mass LOD 10?17 Mo was obtained.

Abstract: Improved apparatus is disclosed for carrying out axially illuminated laser induced fluorescence whole-column imaging detection in the capillary isoelectric focusing of proteins. The separation capillary was made of low refractive index Teflon conditioned with methylcellulose to reduce electroosmotic flow and a small amount of high refractive index organic solvent (glycerol) was added to the sample mixture. It was found that an axially directed laser excitation beam was propagated essentially with total internal reflection, so that minimum interference arose from stray light or from scattering light originating from the wall of the capillary. With the naturally fluorescent protein R-phycoerythrin, a concentration detection limit LOD 10−11 M or mass LOD 10−17 Mo was obtained.