Embodiments include systems, apparatuses, and methods to efficiently separate analytes in a sample and elute fractions of the separated analytes. In some embodiments, a method includes introducing a sample in a capillary with a first end ionically coupled to a first running buffer and a second end ionically coupled to a second running buffer to form a pH gradient. The method includes applying a voltage between the first running buffer and the second running buffer, to separate a plurality of analytes in the sample. The method includes disposing the second end of the capillary in a collection well including a chemical mobilizer and applying a voltage to elute one or more analytes from the plurality of analytes in the sample, that have been separated, into the collection well. Embodiments include detection methods to monitor separation of analytes, mobilization of analytes, and/or elution of fractions containing analytes.

Provided are a method of determining a preconcentration type of an analyte and a method of converting a preconcentration type of an analyte. A method of determining a preconcentration type of an analyte, according to an embodiment of the present invention, includes (a) establishing a critical mobility model, (b) calculating a critical mobility by applying a parameter value to the critical mobility model, and (c) determining the preconcentration type of the analyte by comparing the calculated critical mobility to an absolute value of an electrophoretic mobility of the analyte.

The present disclosure provides icIEF sample matrices that enable icIEF analysis of PEGylated proteins in their real conjugated states. The sample matrices of the present disclosure can include glycine, which enables the separation of co-migrated PEGylated protein charge variants. The sample matrices can also include taurine, whichfurther improves icIEF assay by depleting matrix induced baseline interferences. Accordingly, a sample matrix of the present disclosure including a combination of glycine and taurine enables icIEF separation of acidic and basic species from the main peak for PEGylated proteins, allowing the identification/separation, characterization and quantification of discrete PEGylated protein species. By using the sample matrices of the present disclosure to characterize PEGylated proteins by icIEF, repeatability, linearity, accuracy, sample stability, and method robustness are achieved.

Embodiments of the present disclosure are directed to methods, systems, devices and kits corresponding to a method for analyzing charge variants of a protein such as vascular endothelial growth factor VEGF-Trap.

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.

The present disclosure relates to fluidic systems and devices for processing, extracting, or purifying one or more analytes. These systems and devices can be used for processing samples and extracting nucleic acids, for example by isotachophoresis. In particular, the systems and related methods can allow for extraction of nucleic acids, including non-crosslinked nucleic acids, from samples such as tissue or cells. The systems and devices can also be used for multiplex parallel sample processing.

Methods, devices, and systems for improving the quality of electrospray ionization mass spectrometer (ESI-MS) data are described, as are methods, devices, and systems for achieving improved correlation between chemical separation data and mass spectrometry data.

A separation module operates to fractionate or separate an analyte into fractions according to pI, i.e., pI bands, utilizing capillary isoelectric focusing (“CIEF”) within a first microchannel. The fractions are stacked to form plugs, the number of which is determined by a number of parallel second microchannels integrally connected to the first microchannel, into which the fractions are directed according to the buffer characteristics found in each of the individual microchannels. Within the microchannels the plugs are separated into proteins according to a different chemical property, i.e., “m/z,” utilizing capillary electrophoresis (“CE”).

Methods and devices for purifying, detecting, and collecting analytes fractionated based on pI, separating analytes via electrophoresis and pI, and purifying a target molecule using pI focusing and subsequent crystallization are provided.

Embodiments described herein relate to single-channel free-flow electrophoresis devices or apparatuses, and methods for separating and collecting analytes of interest from a sample by sequentially adjusting the pH value of the electrolyte buffers and separating the analyte of interest according to the corresponding isoelectric points of the analyte of interest. The method includes flowing a sample through a single center channel, applying an electric field perpendicular to a flow direction of the sample via an anolyte channel and a catholyte channel that are parallel to the center channel, and then collecting a fraction of the analyte of interest in accordance with their respective isoelectric points.