Microfluidic device for detection of mitochondrial DNA via fluorescence modulated by hybridization

Abstract

A microfluidic device for analysis of mitochondrial DNA in a sample, the microfluidic device having an inlet for receiving a sample of biological material having cells with mitochondria containing mitochondrial DNA, a lysis section for lysing the mitochondria to release the mitochondrial DNA, fluorescence resonance energy transfer (FRET) probes for hybridization with target nucleic acid sequences in the mitochondrial DNA to form probe-target hybrids, and, a photosensor for detecting the probe-target hybrids.

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

"The present invention provides a microfluidic device for analysis of mitochondrial DNA in a sample. The device includes an inlet for receiving the sample, a lysis section for lysing the mitochondria to release the mitochondrial DNA, fluorescence resonance energy transfer (FRET) probes for hybridization with target nucleic acid sequences in the mitochondrial DNA, and a photosensor for detecting the probe-target hybrids. The device also has a reagent reservoir containing a lysis reagent for lysing the outer cellular membrane and the mitochondrial membrane while the nuclear membrane remains intact, and an array of hybridization chambers for containing the probes. The device also has a nucleic acid amplification section upstream of the array of hybridization chambers, and a microsystems technologies (MST) layer incorporating the lysis section and the hybridization chamber array, CMOS circuitry, and a nucleic acid amplification section for amplifying the target nucleic acid sequences prior to hybridization with the FRET probes. The device also has a fluid flow-path for drawing fluid from the PCR section to a liquid end point sensor, and the hybridization chambers are each configured to fill with the fluid from the fluid flow-path by capillary action. The detection of mitochondrial DNA sequences has the advantage of maintaining high sensitivity and fidelity in old or degraded sample material, and no washing, additional sensitization, or development steps are required to produce a signal whose level changes in the presence of the target."

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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