The present inventive concept relates to a microfluidic system (10) for diluting a sample liquid of a predetermined sample volume. The system (10) comprises: a first sample channel (100) ending in a first valve (110), wherein the first sample channel (100) is arranged to contain the sample liquid of the predetermined volume; a buffer reservoir (120) arranged for receiving a buffer liquid; a timing channel (102) connecting the buffer reservoir (120) and the first valve (110), wherein the timing channel (102) is arranged to draw, by capillary action, buffer liquid from the buffer reservoir (120) to an output (1102) of the first valve (110) and to open the first valve (110), whereby sample liquid present in the first sample channel (100) is allowed to flow through the output (1102) of the first valve (110) together with buffer liquid from the timing channel (102); a buffer channel (104) connecting the buffer reservoir (120) and a second valve (112), wherein the buffer channel (104) is arranged to draw, by capillary action, buffer liquid from the buffer reservoir (120) to a first opening (1122) of the second valve (112); a mixture channel (106) connecting the first valve (110) and the second valve (112), wherein the mixture channel (106) is arranged to draw, by capillary action, liquid from the first valve (110) to a second opening (1124) of the second valve (112); and a first exit channel (108) connected to a third opening (1126) of the second valve (112), wherein the second valve (112) is arranged to be opened when liquid has been drawn to the first opening (1122) or the second opening (1124) of the second valve (112), whereby liquid is allowed to flow between the first opening (1122), the second opening (1124), and the third opening (1126) of the second valve (112), thereby allowing the sample liquid of the predetermined volume to be diluted with buffer liquid.

The present inventive concept relates to a microfluidic system (10) for diluting a sample liquid of a predetermined sample volume. The system (10) comprises: a first sample channel (100) ending in a first valve (110), wherein the first sample channel (100) is arranged to contain the sample liquid of the predetermined volume; a buffer reservoir (120) arranged for receiving a buffer liquid; a timing channel (102) connecting the buffer reservoir (120) and the first valve (110), wherein the timing channel (102) is arranged to draw, by capillary action, buffer liquid from the buffer reservoir (120) to an output (1102) of the first valve (110) and to open the first valve (110), whereby sample liquid present in the first sample channel (100) is allowed to flow through the output (1102) of the first valve (110) together with buffer liquid from the timing channel (102); a buffer channel (104) connecting the buffer reservoir (120) and a second valve (112), wherein the buffer channel (104) is arranged to draw, by capillary action, buffer liquid from the buffer

The invention generally relates to microfluidic devices that include channels that are slidable relative to each other and methods of use thereof. In certain embodiments, the invention provides a microfluidic device that includes a first channel having an open end, and a second channel having an open end. The first and second channels are slidable relative to each other such that when the open end of the first channel and the open end of the second channel are aligned with each other, fluid flows from the first channel into the second channel.

The invention provides mechanical devices that can be used to combine reagents and discover their effects on living cells. A device of the invention holds liquids in open-ended channels and transfers liquids from one channel to another by bringing a second channel into proximity and alignment with an open end of a first channel. Channels of the device can include fluid partitions (e.g., water-oil-water emulsions) that include living cells. The device includes a mechanical system the operation of which causes a receiving channel to pass among supply channels, aligning with each in turn, to pick up chemicals from those channels and make new combinations within the receiving channel. The device then presents those new chemical combinations to the living cells within their respective partitions, thereby allowing for the determination of the effects of those combinations on living cells.

The present disclosure is directed to opposables including a body having a plurality of cavities disposed therein. Each cavity can be designed to contain one or more reagents, liquids, or fluids which may be applied to a specimen-bearing surface. In some embodiments, the cavities include one or more reagent chambers, the reagent chambers can have one or more seals such that the reagents, liquids, or fluids contained therein may be stored and released to the specimen-bearing surface.

A microchannel chip (1) includes: a first channel (201); a reagent holder (230); a gas inlet (210) communicating with the first channel; a lid (50) closing the gas inlet; and a second channel (202) provided downstream of the first channel. A specimen holder (240) is provided downstream of the reagent holder (230). When the lid (50) closes the gas inlet (210), gas is supplied to the first channel (201) and pushes out the reagent downstream from the reagent holder (230). Thus, the pushed-out reagent merges with a specimen in the second channel (202).