Devices and methods for characterization of analyte mixtures are provided. Some methods described herein include performing enrichment steps on a device before expelling enriched analyte fractions from the device for subsequent analysis. Also included are devices for performing these enrichment steps.

Provided herein is technology relating to depositing and/or placing a macromolecule at a desired site for an assay and particularly, but not exclusively, to methods and systems for placing or guiding a macromolecule such as a protein, a nucleic acid, or a protein:nucleic acid complex to an assay site, such as near a nanopore, a nanowell, or a zero mode waveguide.

Devices and methods for characterization of analyte mixtures are provided. Some methods described herein include performing enrichment steps on a device before expelling enriched analyte fractions from the device for subsequent analysis. Also included are devices for performing these enrichment steps.

Methods of detecting the presence of toxins in a sample using electrophoretic separations and of performing electrophoretic separation of complex samples are provided. The method of detecting the presence of toxins includes reacting a sample and a substrate with a signaling enzyme which converts the substrate to the product in a reaction medium, introducing a run buffer into a separation channel having an inlet end, selectively introducing at least one of the substrate and the product of the reaction medium into the inlet end of the separation channel, electrophoretically separating the substrate and the product, and determining the rate of conversion of the substrate to the product, wherein a change in the rate of conversion is indicative of the presence of toxins. The method of performing electrophoretic separations of complex samples having charged particulates and oppositely charged analytes comprising introducing a run buffer into a separation channel having an inlet end, selectively introducing the oppositely charged analytes in the complex sample into the separation channel, and electrophoretically separating the charged particulates and the oppositely charged analytes. Additionally, a device for varying with respect to time the bulk flow of a fluid in a separation channel of an electrophoretic device having a buffer reservoir in fluid contact with the separation channel is provided. The device includes a pressure sensor in fluid contact with a buffer reservoir, a high pressure reservoir in selective fluidic communication with the buffer reservoir, a low pressure reservoir in selective fluidic communication with the buffer reservoir and in fluidic communication with the high pressure reservoir, and a pumping device for pumping a gas from the low pressure reservoir to the high pressure reservoir.

Methods and kits for diagnosing the presence of and prognosing the appearance of tissue remodelling-associated conditions, involving the presence of enzyme complexes in a biological sample, are disclosed. In particular, the method pertains to diagnosing the presence of or prognosing appearance of metastatic cancer by the identification of high molecular weight enzyme complexes comprising MMPs.

Provided herein is technology relating to depositing and/or placing a macromolecule at a desired site for an assay and particularly, but not exclusively, to methods and systems for placing or guiding a macromolecule such as a protein, a nucleic acid, or a protein: nucleic acid complex to an assay site, such as near a nanopore, a nanowell, or a zero mode waveguide.

The present invention provides methods and compositions for labeling, separating and analyzing proteins, particularly a specific protein of interest within a cell lysate or in a mixture of proteins. The proteins are labeled with an amine reactive or thiol reactive fluorescent dye, or an amine reactive fluorogenic reagent that becomes fluorescent upon reacting to amine groups located on the protein. Following the labeling step, the proteins within the mixture can be separated and analyzed. In a further embodiment, a tag binding fluorogenic reagent that can bind to a tag on a tagged protein is added to specifically label the protein of interest.

A method of analyzing an exosome is provided for detecting abnormality in a cell, including: (a) a step of preparing an exosome from a sample; (b) a step of bringing the exosome prepared in the step (a) into contact with a first antibody to a protein which exists on the surface of the exosome as an antigen and forming a first antibody-exosome complex; and (c) a step of measuring a zeta potential of the first antibody-exosome complex.

Disclosed are methods and apparatus for separation of biomolecules via two-dimensional gel electrophoresis, methods and apparatus for immunoblotting separated biomolecules, and methods for the use of biomolecules processed via the methods and apparatus of the present invention, including use in a clinical setting. The methods and apparatus for separation of biomolecules via two-dimensional gel comprises vertical agarose gel electrophoresis in the first dimension, and the electrophoresis of a novel non-denaturing 3-35% concave gradient polyacrylamide gel in the second dimension. This novel gel can be cast in a modified gel caster that can facilitate the pouring of multiple gels simultaneously. The methods and apparatus for immunoblotting are useful with any type of immunoblotting, including Western blot, Northern blot, and Southern blot analyses. These methods and apparatus provide safe, efficient and cost-effective immunoblots, while facilitating the reduction of exposure to toxic or radioactive materials, as well as the disposal of those materials.

Multifunctional molecular weight protein ladders and methods of making thereof are disclosed herein that are useful for determining the molecular weight of a test protein and/or the relative mass or amount of the test protein in a protein separation assay, such as gel electrophoresis or western blotting. Also included are compounds of Formula I (e.g., mono acetylated MP-11 NHS ester) that may be used to label purified proteins of the protein ladder. The MP-11 label protein ladder can be detected on a blotting membrane by exposing the microperoxidase to a suitable substrate, such as a chromogenic substrate or a chemiluminescent substrate.