Methods and systems for processing polynucleotides (e.g., DNA) are disclosed. A processing region includes one or more surfaces (e.g., particle surfaces) modified with ligands that retain polynucleotides under a first set of conditions (e.g., temperature and pH) and release the polynucleotides under a second set of conditions (e.g., higher temperature and/or more basic pH). The processing region can be used to, for example, concentrate polynucleotides of a sample and/or separate inhibitors of amplification reactions from the polynucleotides. Microfluidic devices with a processing region are disclosed.

An example microfluidic device comprises a plurality of fluidic channels and a fluidic multiplexor. The fluidic multiplexor includes a plurality of fluidic micro-valves fluidically coupled to the plurality of fluidic channels, and a plurality of control lines that cross the plurality of fluidic channels proximal to the plurality of fluidic micro-valves.

A microfluidic sealing valve 1 comprises a primary channel 2, a valve channel 4, and a geometry that permits liquid in the primary channel 2 to flow into the valve channel 4 through an inlet 5. Liquid in the primary channel 2 is inhibited from flowing through a first port 8 into the void volume 7. A meniscus 9 moved by a flow of liquid in the primary channel 2 is restrained at the first port 8. A flow of liquid through the primary channel 2 generates a capillary force that causes the flow of liquid to flow into the valve channel 4. A capillary force generated by the flow of liquid through the valve channel 4 causes the meniscus 9 to expand from the first port 8 into the primary channel, to inhibit flow of liquid in the primary channel 2 past the first port 8.

Provided is a rotatable microfluidic device for conducting simultaneously two or more assays. The device includes a platform which can be rotated, a first unit which is disposed at one portion of the platform and detects a target material from a sample using surface on which a capture probe selectively binds to the target material is attached, and a second unit which is disposed at another portion of the platform and detects a target material included in the sample by a different reaction from the reaction conducted in the first unit.

A microfluidic valve comprises a first reservoir, a second reservoir, an inertial pump and a channel connecting the first reservoir to the second reservoir. The second reservoir is to receive fluid from the first reservoir through the channel under a pressure gradient. The inertial pump is within the channel proximate the second reservoir and distant the first reservoir.

The present disclosure is drawn to microfluidic chips. The microfluidic chips can include an inflexible material having an elastic modulus of 0.1 gigapascals (GPa) to 450 GPa. A microfluidic channel can be formed within the inflexible material and can connect an inlet and an outlet. A working electrode can be associated with the microfluidic channel and can have a surface area of 1 μm.sup.2 to 60,000 μm.sup.2 within the microfluidic channel. A bubble support structure can also be formed within the microfluidic channel such that the working electrode is positioned to electrolytically generate a bubble that becomes associated with the bubble support structure.

A reversible micro-valve device includes a main channel, a passage comprising an opening in fluid communication with the main channel, and a side chamber to house a volume of trapped gas. The side chamber is communicably attached to the passage to control flow along the main channel. The side chamber is to be larger in volume than the main channel to which the trapped gas expands and includes one of the following two states at a given time: an open state in which the main channel is open and flow proceeds through the main channel, or a closed state in which the trapped gas within the side chamber is to expand within the passage and block the flow in the main channel.

Methods and systems for processing polynucleotides (e.g., DNA) are disclosed. A processing region includes one or more surfaces (e.g., particle surfaces) modified with ligands that retain polynucleotides under a first set of conditions (e.g., temperature and pH) and release the polynucleotides under a second set of conditions (e.g., higher temperature and/or more basic pH). The processing region can be used to, for example, concentrate polynucleotides of a sample and/or separate inhibitors of amplification reactions from the polynucleotides. Microfluidic devices with a processing region are disclosed.

Examples include microfluidic devices. Example microfluidic devices comprise a microfluidic channel, a capillary chamber, and a fluidic actuator. The microfluidic channel is fluidly connected to the capillary chamber. The capillary chamber is to restrict flow of fluid therethrough. The fluidic actuator is positioned proximate the capillary chamber. The fluidic actuator is to actuate to thereby initiate flow of fluid through the capillary chamber.

A microfluidic valve may include a firing chamber having an orifice, a first portion of a liquid conduit connected to the firing chamber at a first port, a second portion of the liquid conduit connected to the firing chamber at a second port and a thermal resistor. The thermal resistor is to form a bubble within the firing chamber to expel liquid from the firing chamber through the orifice such that a first meniscus forms across the first port and a second meniscus forms across the second port to interrupt liquid flow between the first portion and the second portion of the liquid conduit.