A microfluidic arrangement for manipulating fluids is provided. The microfluidic arrangement comprises a substrate, a first fluid and a second fluid, which is immiscible with the first fluid. The first fluid is arranged to be at least partially covered by the second fluid. The first fluid is arranged in a desired shape on an unpatterned surface of the substrate. The first fluid is retained in said shape by a fluid interface between the first and second fluids. A microfluidic arrangement comprising an array of drops is also provided. The microfluidic arrangement comprises a substrate, a first fluid and a second fluid, which is immiscible with the first fluid. The first fluid is arranged to be at least partially covered by the second fluid. The first fluid is arranged to be covered at least partially by the second fluid. The first fluid is arranged in a given array of drops on an unpatterned surface of the substrate. Each drop cross section area having a (height:width) aspect ratio of (1:2) or less. A method of fabricating a microfluidic arrangement for manipulating fluids is also provided. The method comprises arranging a first fluid on an unpatterned surface of a substrate in a desired shape. The method also comprises arranging a second fluid, which is immiscible with the first fluid, to cover the first fluid at least partially. The first fluid is retained in said shape by a fluid interface between the first and second fluids. The method also comprises drying the first fluid to form a residue in said shape on the substrate.

Provided is an apparatus for generating a microfluidic concentration field, the apparatus including: a substrate; a base film disposed on the substrate; a microchannel, which is formed in a space between the substrate and the base film and through which a fluid flows; a through passage, which communicates with the microchannel and is configured to pass through the base film; and a membrane, which is formed at a portion where the microchannel and the through passage communicate with each other and allows the fluid flowing along the microchannel and the through passage or a material flowing together with the fluid to selectively pass through the membrane, wherein a concentration field is formed between the fluid of the through passage and the fluid of the microchannel by the membrane.

A reaction processing vessel includes: a substrate; a channel for a sample to move that is formed on the substrate; a first air communication port and a second air communication port provided at respective ends of the channel; and a thermal cycle region for applying a thermal cycle to the sample that is formed between the first air communication port and the second air communication port in the channel. The channel includes a first branch channel and a second branch channel between the thermal cycle region and the first air communication port.

The present disclosure relates to devices and systems for separating motile pathogenic bacterial cells from samples. The disclosure also provides for methods of determining whether a sample is contaminated by pathogenic bacteria. The devices and systems disclosed herein are useful for screening water sources, environmental testing sites, food sources, and bodily fluids for the presence, absence, or quantity of bacterial cells in a sample representative of the screened sources.

The disclosure provides a method of manipulating droplets in an electro-wetting on dielectric (EWOD) device. Electro-wetting electrodes of the EWOD device are selectively actuated to: cause first and second droplets in a fluid medium in the fluid chamber of the EWOD device to contact each other to form a droplet interface bilayer, the first droplet containing fluid of a first composition including a first solute species and the second droplet containing fluid of a second composition different to the first composition, maintain the first and second droplets contacting each other to maintain the droplet interface bilayer and thereby allow the first solute species to pass from the first droplet to the second droplet via the DIB; and cause the first droplet to separate from the second droplet. This method aspect results in transfer of solute from the first droplet to the second droplet. This provides a convenient way of altering the concentration of a particular component or components in a fluid droplet within an EWOD device. This allows, for example, an undesired solute species to be extracted from a reaction droplet or the undesired solute species to be diluted in the reaction droplet before the droplet undergoes further reaction steps.

An embodiment for a microfluidic device is provided. The device comprises two areas, arranged side-by-side, and a trigger channel. They include a first area, which is delimited by a first liquid pinning barrier, and a second area, which is delimited by a second liquid pinning barrier. The latter extends parallel to the first liquid pinning barrier to delimit a corridor. The trigger channel extends through the corridor between the two areas. In addition, the trigger channel connects the first liquid pinning barrier with the second liquid pinning barrier, allowing a first liquid pinned at the first liquid pinning barrier and a second liquid pinned at the second liquid pinning barrier to be contacted, each, by a reverse flow of the second liquid in the trigger channel and thereby start mixing at a level of the corridor, in operation. The invention is further directed to related methods of operation.

A method for determining a biological response of a target (41, 42) to a soluble candidate substance includes the steps: introducing a soluble candidate substance into a laminar flow of a buffer liquid (2) to form a candidate substance solute (3) having an initial concentration profile (31); dispersing the initial concentration profile (31) to form a dispersed concentration profile (32); directing the dispersed concentration profile (32) into a detection channel (12) to form a final symmetrical concentration profile (33) therein; introducing a target into the detection channel (12) to obtain a combined concentration profile including a constant target concentration profile overlying the final symmetrical concentration profile (33); holding in the detection channel (12) at least one half of the combined concentration profile; and optically scanning the combined concentration profile to detect an optical signal representative of the biological response of the target to the soluble candidate substance.

Techniques, systems, and devices are disclosed for non-thermal cycling of polymerase chain reaction (PCR). In one aspect, a method for cycling PCR includes receiving an electrolytic fluid including ions, primers, polymerase enzymes, nucleotides, and a double-stranded nucleic acid in a fluid chamber having a first electrode and a second electrode, applying an electric field across the first and the second electrodes to generate a first pH level of the electrolytic fluid to denature the double-stranded nucleic acid to at least partial single strands, and applying a second electric field across the first and second electrodes to produce a second pH level of the electrolytic fluid, in which the second pH level enables binding of a polymerase enzyme and a primer with a corresponding segment of the single strands.

In one embodiment, a selective plane illumination microscopy system for capturing light emitted by an illuminated specimen includes a specimen stage having a top surface adapted to support a specimen holder and an opening adapted to provide access to a bottom of the holder, and a selective plane illumination microscopy optical system positioned beneath the stage, the optical system including an excitation objective, a detection objective, and an open-top, hollow prism that is adapted to contain a quid, wherein the prism is positioned within the opening of the stage and optical axes of the objectives are aligned with the prism such that the axes pass through the prism and intersect at a position near the top surface of the specimen stage.

A microfluid device for producing diffusively built gradients comprising a bottom plate and a cover plate, wherein the cover plate has recesses and is connected to the bottom plate in a liquid-tight manner so that the recesses form at least two reservoirs and one observation chamber, which connects the reservoir, a reservoir can be filled particularly through an inlet/outlet through the cover plate, and the cross-sectional surface of the observation chamber is at least 5 times, preferably at least 200 times smaller at the aperture of the observation chamber into one of the reservoirs than the maximum cross-sectional surface of the reservoir in parallel to this cross-sectional surface of the observation chamber.