Disclosed are methods for performing capillary electrophoresis on two or more nucleic acid samples. The methods employ a forward voltage to move a first sample forward from an inlet to an interrogation region in the capillary, then a backward voltage to move the first sample backward, and then a forward voltage again to move the first sample and a second sample forward. Systems and apparatuses for performing capillary electrophoresis are also provided.

The present disclosure generally relates to devices for effecting epitachophoresis. Epitachophoresis may be used to effect sample analysis, such as by selective separation, detection, extraction, and/or pre-concentration of target analytes such as, for example, DNA, RNA, and/or other biological molecules. Said target analytes may be collected following epitachophoresis and used for desired downstream applications and further analysis.

A horizontal electrophoresis apparatus according to the present invention comprises a first electrode and a second electrode arranged at respective sides of an electrophoretic gel and each in close contact with one side of the electrophoretic gel. By using the first electrode and the second electrode each in close contact with one side of the electrophoretic gel, the horizontal electrophoresis apparatus enables electric current to flow across the entire cross section of the electrophoretic gel, and thus can prevent an electric current difference from occurring between the upper and lower ends of the electrophoretic gel and solve the problem of a reduction in the resolution of protein bands.

Techniques described herein can apply AC signals with different phases to different groups of nanopore cells in a nanopore sensor chip. When a first group of nanopore cells is in a dark period and is not sampled or minimally sampled by an analog-to-digital converter (ADC) to capture useful data, a second group of nanopore cells is in a bright period during which output signals from the second group of nanopore cells are sampled by the analog-to-digital converter. The reference level setting of the ADC is dynamically changed based on the applied AC signals to fully utilize the dynamic range of the ADC.

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.

The present invention provides an electrophoresis device with improved abnormality detection capability. The electrophoresis device according to the present invention includes a flow passage with which a phoresis medium is filled, a first and second electrodes disposed at respectively a cathode side and an anode side of the flow passage, a power supply for applying voltage across the first and second electrodes, a pump for feeding the phoresis medium to the flow passage, and a control section. The control section executes operations including filling the flow passage with the phoresis medium, executing electrophoresis of a sample, and applying voltage to the first and second electrodes prior to the sample electrophoresis to determine a state of a current path based on a value of current flowing through the current path. The control section applies voltage to the current path for 20 seconds or longer in the determine step.

A system and method for detecting a single-molecule using an integrated circuit which includes at least one membrane having a nanopore located between first and second reservoirs and a low-noise preamplifier having an electrode formed on the surface thereof is provided. The method includes passing a target molecule through the nanopore, and measuring a current through the nanopore to detect the presence of a biomolecular entity, if any.

An electric field gradient focusing device is provided that includes: (i) a fluidic channel having an inlet and an outlet for a fluid, (ii) a first actuator configured to induce a fluid flow in the fluidic channel from the inlet to the outlet via AC electroosmosis, and (iii) a second actuator configured to generate a DC electric field gradient along at least part of the fluidic channel.

Various implementations of electrophoretic systems and instruments are provided to improve electrophoresis and ease of use. Various electrophoretic systems and instruments utilize different electrode designs that can result in uniform electromigration of analytes. The electrophoretic systems and instrumentations optimize the size and/or location of electrodes relative to a sample, thereby increasing uniformity of electric field and reducing or minimizing drift of analyte migration. In addition, the electrophoresis systems and instruments provide a solution to conveniently check for electrical connections in the systems and instruments, and alert users of potential improper electrical connections, prior to performing electrophoresis.

The present disclosure provides electrophoretic systems, methods and compositions for spatial analysis, which can serve to magnify or demagnify spatial resolution of analytes of interest that are captured using electrophoresis. Some implementations can use a diverging or converging electric field in an electrophoretic capture system. Such a divergent or convergent electric field, as opposed to a parallel electric field, can be generated by, for example, utilizing different sizes of electrodes associated with or imbedded in substrates. Also provided herein are electrophoretic systems, methods and compositions for spatial analysis, which can serve to selectively migrate one or more analytes from a region of interest in the biological sample for capture using electrophoresis.