The present invention generally pertains to methods of characterizing charge variants of a protein of interest. In particular, the present invention pertains to the use of desalting size exclusion chromatography-reduced peptide mapping mass spectrometry to identify charge variants separated by capillary isoelectric focusing.

The present invention generally pertains to methods of characterizing charge variants of a protein of interest. In particular, the present invention pertains to the use of desalting size exclusion chromatography-reduced peptide mapping mass spectrometry to identify charge variants separated by capillary isoelectric focusing.

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.

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.

Some embodiments described herein relate to a method that includes separating an analyte-containing sample via electrophoresis in a capillary. The capillary is loaded with a chemiluminescence agent, such as luminol, that is configured to react with the analyte (e.g., HRP-conjugated proteins) to produce a signal indicative of a concentration and/or quantity of analyte at each location along the length of the capillary. A first image of the capillary containing the analytes and the chemiluminescence agent is captured over a first period of time. A second image of the capillary containing the analytes and the chemiluminescence agent is captured over a second, longer, period of time. A concentration and/or quantity of a first population of analytes at a first location is determined using the first image, and a concentration and/or quantity of a second population of analytes at a second location is determined using the second image.

Some embodiments described herein relate to a method that includes separating an analyte-containing sample via electrophoresis in a capillary. The capillary is loaded with a chemiluminescence agent, such as luminol, that is configured to react with the analyte (e.g., HRP-conjugated proteins) to produce a signal indicative of a concentration and/or quantity of analyte at each location along the length of the capillary. A first image of the capillary containing the analytes and the chemiluminescence agent is captured over a first period of time. A second image of the capillary containing the analytes and the chemiluminescence agent is captured over a second, longer, period of time. A concentration and/or quantity of a first population of analytes at a first location is determined using the first image, and a concentration and/or quantity of a second population of analytes at a second location is determined using the second image.

The present invention discloses a gel electrophoresis chip, comprising a first substrate, a first plurality of parallel gel strips formed on the first substrate, respectively extending along a first direction and having a certain width; and a second plurality of isolation segments formed on the first substrate, respectively located between adjacent gel strips and extending along a second direction different from the first direction, the isolation segments being arranged to form a microwell array together with the gel strips. After the gel electrophoresis chip achieves conventional protein two-dimensional gel electrophoretic separation, protein samples suitable for mass spectrometry analysis are prepared in high throughput, thus greatly reducing the pretreatment time of mass spectrometry analysis, thereby being suitable for proteomic analysis of biological samples.

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.

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.

Described herein are methods of separating lipid nanoparticles (LNPs) according to their isoelectic points, the methods comprising applying a separating voltage to a separation matrix comprising carrier ampholytes and the LNPs for a sufficient time to separate the LNPs according to their isoelectic points.