Method and apparatus for determining internal structural properties of a polymer molecule by measuring the force required to translocate the molecule through the interface between two fluids. In some cases, the fluid interface may have a well-defined curvature, which may be held constant or otherwise controlled during translocation. In some cases, the translocating force may be modulated at one or more frequencies. In some cases, attachment of the molecule to a manipulator may be detected before or during translocation.

This disclosure relates to methods and devices to count particles of interest, such as cells. The methods include obtaining a fluid sample that may contain particles of interest; counting all types of particles in a portion of the sample using a first electrical differential counter to generate a first total; removing any particles of interest from the portion of the fluid sample; counting any particles remaining in the portion of the fluid sample using a second electrical differential counter after the particles of interest are removed to generate a second total; and calculating a number of particles of interest originally in the fluid sample by subtracting the second total from the first total, wherein the difference is the number of particles of interest in the sample. These methods and related devices can be used, for example, to produce a robust, inexpensive diagnostic kit for CD4+ T cell counting in whole blood samples.

An active sieve device for the isolation and characterization of bio-analytes is provided, comprising a substrate for supporting the bio-analytes. The substrate comprises a plurality of interconnections and a plurality of regions, each region comprising a hole and at least one electrode embedded in or located on the substrate and electrically associated with the hole. Each region further comprises at least one transistor integrated in the substrate and operably connected to the at least one electrode and to at least one of the plurality of interconnections.

A method of forming a plurality of lipid bilayers over an array of cells in a nanopore based sequencing chip is disclosed. Each of the cells comprises a well. A first salt buffer solution with a first osmolarity is flowed over a cell in the nanopore based sequencing chip to substantially fill a well in the cell with the first salt buffer solution. A lipid and solvent mixture is flowed over the cell to deposit a lipid membrane over the well that encloses the first salt buffer solution in the well. A second salt buffer solution with a second osmolarity is flowed above the well to reduce the thickness of the lipid membrane, wherein the second osmolarity is a lower osmolarity than the first osmolarity such that an osmotic imbalance is created between a first volume inside the well and a second volume outside the well.

A method of forming a plurality of lipid bilayers over an array of cells in a nanopore based sequencing chip is disclosed. Each of the cells comprises a well. A first salt buffer solution with a first osmolarity is flowed over a cell in the nanopore based sequencing chip to substantially fill a well in the cell with the first salt buffer solution. A lipid and solvent mixture is flowed over the cell to deposit a lipid membrane over the well that encloses the first salt buffer solution in the well. A second salt buffer solution with a second osmolarity is flowed above the well to reduce the thickness of the lipid membrane, wherein the second osmolarity is a lower osmolarity than the first osmolarity such that an osmotic imbalance is created between a first volume inside the well and a second volume outside the well.

This disclosure relates to methods and devices to count particles of interest, such as cells. The methods include obtaining a fluid sample that may contain particles of interest; counting all types of particles in a portion of the sample using a first electrical differential counter to generate a first total; removing any particles of interest from the portion of the fluid sample; counting any particles remaining in the portion of the fluid sample using a second electrical differential counter after the particles of interest are removed to generate a second total; and calculating a number of particles of interest originally in the fluid sample by subtracting the second total from the first total, wherein the difference is the number of particles of interest in the sample. These methods and related devices can be used, for example, to produce a robust, inexpensive diagnostic kit for CD4+ T cell counting in whole blood samples.

This disclosure relates to methods and devices to count particles of interest, such as cells. The methods include obtaining a fluid sample that may contain particles of interest; counting all types of particles in a portion of the sample using a first electrical differential counter to generate a first total; removing any particles of interest from the portion of the fluid sample; counting any particles remaining in the portion of the fluid sample using a second electrical differential counter after the particles of interest are removed to generate a second total; and calculating a number of particles of interest originally in the fluid sample by subtracting the second total from the first total, wherein the difference is the number of particles of interest in the sample. These methods and related devices can be used, for example, to produce a robust, inexpensive diagnostic kit for CD4+ T cell counting in whole blood samples.

A method of forming a plurality of lipid bilayers over an array of cells in a nanopore based sequencing chip is disclosed. Each of the cells comprises a well. A first salt buffer solution with a first osmolarity is flowed over a cell in the nanopore based sequencing chip to substantially fill a well in the cell with the first salt buffer solution. A lipid and solvent mixture is flowed over the cell to deposit a lipid membrane over the well that encloses the first salt buffer solution in the well. A second salt buffer solution with a second osmolarity is flowed above the well to reduce the thickness of the lipid membrane, wherein the second osmolarity is a lower osmolarity than the first osmolarity such that an osmotic imbalance is created between a first volume inside the well and a second volume outside the well.

According to one embodiment, an analysis chip for detection of particles in a sample liquid includes a substrate, a channel provided on a surface portion of the substrate, a liquid storage portion provided on a part of the channel to store the sample liquid, holes being provided at a bottom portion of the liquid storage portion to connect the liquid storage portion and the channel, and first electrodes provided in the channel or the liquid storage portion.

The device (100) comprises a cavity (101) and at least two microporous membranes (102), wherein the microporous membranes (102) are arranged in series in the cavity (101) and divide the cavity (101) into a plurality of chambers (1011); each of the microporous membranes (102) is provided with micropores (103), and two adjacent chambers (1011) are in communication via the micropores (103); and each of the chambers (1011) is provided with an electrode (1012).