Fluidic Test Cassette

Abstract

A disposable cassette for detecting nucleic acids or performing other assays. The cassette can be inserted into a base station during use. The cassette has numerous features to ensure correct operation of the device under gravity, such as vent pockets for enabling the flow of sample fluid from one chamber to the next when the vent pocket is unsealed. The vent pockets have protrusions to help prevent accidental resealing. The cassette also can have a gasket to ensure free air movement between open vent pockets. A flexible circuit with patterned metallic electrical components disposed on a heat stable material can be in direct contact with fluid in the chambers and has resistive heating elements aligned with the vent pockets and the chambers. The detection chamber, which houses a lateral flow detection strip can have a space below the strip that has sufficient capacity to accommodate an entire volume of the sample fluid entering the detection chamber at a height that enables the fluid to flow up the detection strip by capillary action without flooding or otherwise bypassing regions of the detection strip. The space can also contain detection particles. Recesses in in the cassette channels or chambers can have structures such as ridges or grooves to direct fluid flow to enhance rehydration of lyophilized reagents disposed in the recess. Flow diverters in the chambers can reduce the flow velocity of the sample fluid and increase the effective fluid flow path length, enabling more accurate control of fluid flow in the cassette.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to and the benefit of filing of U.S. Provisional Patent Application Ser. No. 62 / 152,724, entitled “Fluidic Test Cassette”, filed on Apr. 24, 2015, and U.S. Provisional Patent Application Ser. No. 62 / 322,738, entitled “Fluidic Test Cassette”, filed on Apr. 14, 2016, the specifications and claims of which are incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention (Technical Field)[0003]Embodiments of the present invention relate to an integrated device and related methods for detecting and identifying nucleic acids. The device may be fully disposable or may comprise a disposable portion and a reusable portion.[0004]2. Background Art[0005]Note that the following discussion may refer to a number of publications and references. Discussion of such publications herein is given for more complete background of the scientific principles and is not to be construed as an admission ...

AI Technical Summary

Benefits of technology

The present invention provides a cassette for detecting a target nucleic acid, which includes a detection chamber and a lateral flow detection strip. The cassette is designed to prevent excess fluid from flowing directly through the outlet, resulting in improved mixing and dispersion of detection particles with the amplified target nucleic acid. The vertical flow of fluid through the cassette is controlled by deflecting the fluid flow at the top of the chamber, reducing the flow velocity and creating a swirl within the chamber. The invention also provides a method to increase the effective path length and reduce the flow velocity of fluid in the channel, improving the detection of target nucleic acid.

Problems solved by technology

Unfortunately, currently available nucleic acid tests are unsuitable or of limited utility for field use because they require elaborate and costly instrumentation, specialized laboratory materials and / or multiple manipulations dependent on user intervention.

Consequently, most samples for molecular testing are shipped to centralized laboratories, resulting in lengthy turn-around-times to obtain the required information.

Unfortunately, dependence upon elaborate instrumentation imposes tremendous economic barriers for small clinics, local and state government and law enforcement agencies.

Further, dependence upon a small number of instruments to run tests could cause unnecessary delays during periods of increased need, as occurs during a suspected biowarfare agent release or an emerging epidemic.

Indeed, the instrument and disposable reagent cartridge model presents a potentially significant bottleneck when an outbreak demands surge capacity and increased throughput.

Additionally, instrumentation dependence complicates ad hoc distribution of test devices to deployment sites where logistic constraints preclude transportation of bulky associated equipment or infrastructure requirements are absent (e.g. reliable power sources).

However, the typical device does not allow for programmable or electronic control of such fluid movement, or the mixing of more than two fluids.

Also, some devices utilize a pressure drop generated by a falling inert or pre-packaged fluid to induce a slight vacuum and draw reactants into processing chambers when oriented vertically, which increases storage and transport complexities to ensure stability of the pre-packaged fluids.

Existing devices which teach moving a fluid in a plurality of discrete steps require frangible seals or valves between chambers, which complicates operation and manufacture.

These devices do not teach the use of separate, remotely located vents for each chamber.

The result of the smaller reaction volume is a reduction in capacity to accommodate sufficient specimen volume to ensure the presence of detectable amounts of target in dilute specimens or where assay targets are scarce.

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