Microfluidic devices and nanobiosensors comprising a magnetic nanoparticle attached to a reporter molecule via a release unit for microfluidic-based detection of a target analyte in a biological sample. The nanobiosensor can be magnetically manipulated or guided through the microfluidics channels for incubation with the biological sample, concentration of the nanobiosensors, and detection of target analytes, without having to pump the entire initial sample through the microfluidic channel. The magnetic nanoparticles are separated from the reporter molecules before detection and can be re-used.

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.

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.

Disclosed in the present invention is a method for preparing and certifying a novel coronavirus nucleocapsid protein (nCOV N protein) reference material, the method including: purification and dilution of a raw material of the nCOV N protein; preliminary uniformity test and packaging of solution of a candidate nCOV N protein reference material; characterization of physicochemical properties of the solution of the candidate nCOV N protein reference material in the packaging units; uniformity and stability test of the nCOV N protein reference material in the packaging unit; measurement of standard N protein content of the nCOV N protein reference material, determination and statistical test of standard value of the nCOV N protein reference material; and uncertainty assessment of certified result of the standard value of the nCOV N protein reference material.

Disclosed in the present invention is a method for preparing and certifying a novel coronavirus nucleocapsid protein (nCOV N protein) reference material, the method including: purification and dilution of a raw material of the nCOV N protein; preliminary uniformity test and packaging of solution of a candidate nCOV N protein reference material; characterization of physicochemical properties of the solution of the candidate nCOV N protein reference material in the packaging units; uniformity and stability test of the nCOV N protein reference material in the packaging unit; measurement of standard N protein content of the nCOV N protein reference material, determination and statistical test of standard value of the nCOV N protein reference material; and uncertainty assessment of certified result of the standard value of the nCOV N protein reference material.

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.

The invention provides a capillary isoelectric focusing (cIEF) system based on a sandwich injection method for automated chemical mobilization. This system was coupled with an electrokinetically pumped nanoelectrospray interface to a mass spectrometer. The nanoelectrospray emitter employed an acidic sheath electrolyte. To realize automated focusing and mobilization, a plug of ammonium hydroxide was first injected into the capillary, followed by a section of mixed sample and ampholyte. As focusing progressed, the NH.sub.3H.sub.2O section was titrated to lower pH buffer by the acidic sheath buffer. Chemical mobilization started automatically once the ammonium hydroxide was consumed by the acidic sheath flow electrolyte.

The invention provides a capillary isoelectric focusing (cIEF) system based on a sandwich injection method for automated chemical mobilization. This system was coupled with an electrokinetically pumped nanoelectrospray interface to a mass spectrometer. The nanoelectrospray emitter employed an acidic sheath electrolyte. To realize automated focusing and mobilization, a plug of ammonium hydroxide was first injected into the capillary, followed by a section of mixed sample and ampholyte. As focusing progressed, the NH.sub.3H.sub.2O section was titrated to lower pH buffer by the acidic sheath buffer. Chemical mobilization started automatically once the ammonium hydroxide was consumed by the acidic sheath flow electrolyte.

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.

The present invention relates to the field of proteomics and more specifically to a method for analyzing a sample possible containing peptides or modified peptides; in particular useful for biomarker discovery or validation of biomarkers. The method uses isoelectric focusing and mass spectrometry (MS) and enables identification of modified peptides with high resolution and predictability.