Microfluidic device with flow-channel structure for capillary-driven fluidic propulsion without trapped air bubbles

Abstract

A microfluidic device for processing a fluid sample, the microfluidic device having a first channel configured to fill with the sample by capillary action, a second channel configured to fill with the sample by capillary action, a plurality of fluid connections between the first channel and the second channel, each of the fluid connections being configured to pin a meniscus of the sample that arrests capillary flow between the first channel and the second channel, a bypass channel between the first channel and the second channel, the bypass channel joining the second channel upstream of the plurality of fluid connections and is configured for uninterrupted capillary driven flow from the first channel to the second channel, wherein during use, flow from the bypass channel reaches the meniscus pinned at each of the fluid connections after the meniscus has formed such that the flow sequentially removes each of the menisci and sample flow from the first channel to the second channel is via the plurality of fluid connections as well as the bypass channel.

Description

FIELD OF THE INVENTION[0001]The present invention relates to diagnostic devices that use microsystems technologies (MST). In particular, the invention relates to microfluidic and biochemical processing and analysis for molecular diagnostics.CO-PENDING APPLICATIONS[0002]The following applications have been filed by the Applicant which relate to the present application:GBS001USGBS002USGBS003USGBS005USGBS006USGSR001USGSR002USGAS001USGAS002USGAS003USGAS004USGAS006USGAS007USGAS008USGAS009USGAS010USGAS012USGAS013USGAS014USGAS015USGAS016USGAS017USGAS018USGAS019USGAS020USGAS021USGAS022USGAS023USGAS024USGAS025USGAS026USGAS027USGAS028USGAS030USGAS031USGAS032USGAS033USGAS034USGAS035USGAS036USGAS037USGAS038USGAS039USGAS040USGAS041USGAS042USGAS043USGAS044USGAS045USGAS046USGAS047USGAS048USGAS049USGAS050USGAS054USGAS055USGAS056USGAS057USGAS058USGAS059USGAS060USGAS061USGAS062USGAS063USGAS065USGAS066USGAS067USGAS068USGAS069USGAS070USGAS080USGAS081USGAS082USGAS083USGAS084USGAS085USGAS086USGAS087USGAS...

AI Technical Summary

Benefits of technology

[0090]The easily usable, mass-producible, and inexpensive microfluidic device accepts a biochemical sample, uses a dialysis section for separating the cells of different dimensions, and separately processes the nucleic acid content of the cells separated based on their dimensions.

[0091]The dialysis section functionality extracts additional information from the sample and increases the sensitivity, signal-to-noise ratio, and dynamic range of the assay system. The dialysis section being integral to the device, provides for the low system component-count and simple manufacturing procedures, leading into an inexpensive assay system. The special flow-channel structure provides for capillary-driven priming of the dialysis section without trapped air bubbles.

Problems solved by technology

Insufficient stringency can result in a high degree of nonspecific binding.

Excessive stringency can lead to a failure of appropriate binding, which results in diminished sensitivity.

Despite the advantages that molecular diagnostic tests offer, the growth of this type of testing in the clinical laboratory has been slower than expected and remains a minor part of the practice of laboratory medicine.

This is primarily due to the complexity and costs associated with nucleic acid testing compared with tests based on methods not involving nucleic acids.

However, controlling fluid flow through the LOC device, adding reagents, controlling reaction conditions and so on necessitate bulky external plumbing and electronics.

Connecting a LOC device to these external devices effectively restricts the use of LOC devices for molecular diagnostics to the laboratory setting.

The cost of the external equipment and complexity of its operation precludes LOC-based molecular diagnostics as a practical option for point-of-care settings.

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