The presently disclosed subject matter relates to compositions, systems and methods of screening one or more species of polypeptide in a complex mixture of polypeptides, e.g., multi-subunit proteins. For example, the subject matter relates to ligands used in connection with affinity capillary electrophoresis, as well as methods and systems for detecting polypeptides in a mixture of multimers that include multispecific antibodies, e.g., bispecific antibodies.

A high-throughput multiplexing electrophoretic gel system is disclosed. The system includes a gel casting device which includes an interior, gel casting chamber by which a polymerized gel layer is formed. The polymerized gel layer includes a plurality of integrally formed sample loading wells. The wells are aligned to be simultaneously loaded with samples via an automated microliter multi-pipette sample loader. The sample-loaded gel layer is adapted to undergo immersed horizontal electrophoresis separation.

An electrophoresis system includes a plurality of capillaries in which electrophoresis of a sample is performed, a light source that irradiates detection positions of the capillaries with light, a light detector that detects light generated by the irradiation with the light by the light source that depends on components contained in the sample, and a buffer storage unit into which one end of the plurality of capillaries are inserted at a time of the electrophoresis of the sample and in which a buffer is stored. A computer controls an electrophoresis condition of each of the plurality of capillaries such that arrival times for the components that move in the plurality of capillaries to reach the detection positions are shifted from each other. As a result, it is possible to detect fluorescence signals at different timings in each of the plurality of capillaries.

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.

Provided herein is an electrophoresis separation medium comprising: (a) a non-crosslinked or sparsely cross-linked polymer or copolymer; (b) one or more denaturant compounds, in an amount sufficient to inhibit re-naturation of single stranded polynucleotides; (c) an aqueous solvent; (d) optionally, a wall-coating material suited to inhibition of electroosmotic flow; and (e) optionally, an organic water miscible solvent such as DMSO or acetonitrile, wherein the electrophoresis separation medium exhibits functional stability for at least seven days at 23° C. Also provided herein are sieving compositions, including polymer-based sieving compositions, for molecular sieving as well as related kits, devices and methods of use. Such compositions can be useful for separation of biomolecules such as nucleic acids, proteins, glycoproteins and glycans.

[Problem] To provide a lactase solution having excellent thermal stability.

[Solution] A lactase solution in which the ratio of a lactase fraction having a molecular weight of about 120 kDa measured by SDS polyacrylamide gel electrophoresis is 20% or more.

This disclosure relates to mesofluidic devices and methods for eluting and concentrating a plurality of nucleic acid molecules. The mesofluidic device includes a device frame having a bottom surface upon which is defined a first reservoir and the second reservoir. The first reservoir includes a first electrode, and the second reservoir includes a second electrode. The first and second electrodes are configured for electrical connection. The mesofluidic device includes an elongated channel extending between the first reservoir and the second reservoir. The mesofluidic device includes a first slot having a first slot width. The first slot is configured to receive an insert. The first slot intersects the elongated channel. The mesofluidic device includes a second slot having a second slot width. The second slot is configured to receive a separation material having a first porosity. The second slot intersects the elongated channel.

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.

The present invention provides a method for determining whether or not a capillary filled with an electrophoretic medium is suitably used for electrophoresis before electrophoresis is performed using the analytes. The method comprises (a) applying an alternating-current voltage between a first electrode which is in contact with a first electrolyte solution in which one end of the capillary is immersed and a second electrode which is in contact with a second electrolyte solution in which the other end of the capillary is immersed to measure an electric conductivity of the electrophoresis medium with which an inside of the capillary is filled; and (b) determining that the capillary filled with the electrophoresis medium fails to be used suitably for the electrophoresis, when the electric conductivity is more than 4.2 mS/cm.

Proteins that are electrophoretically separated in a gel are derivatized to produce fluorescent emissions by incorporating halo-substituted organic compounds into one or both of the electrode buffer solutions at the two ends of the gel. The halo-substituted compounds used are ones that bear an electric charge at the pH of the buffer solutions and gel, and the polarity of the charge on the compounds is such that the compounds migrate from the electrode buffer into the gel under the electrophoretic influence concurrently with the migration of the proteins into the gel. Once the proteins are separated and distributed within the gel and the gel is fully penetrated with the halo-substituted compounds, the gel is irradiated with ultraviolet light to induce a reaction between the halo-substituted compounds and the proteins through the tryptophan residues on the proteins, producing fluorescent reaction products.