Microfluidic Chip With Dual Heating Zones for Rapid Nucleic Acid Amplification
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Solution Overview
Problem
Conventional PCR devices have inefficient heating and cooling ramp rates, leading to long amplification times and reduced sensitivity, limiting their application in rapid clinical testing.
Innovation Solution
A microfluidic device with a microfluidic chip and a heating plate featuring two constant-temperature zones, combined with a sample compartment and oligonucleotides on a capture surface, allows for rapid nucleic acid amplification by moving the sample between these zones, enhancing sensitivity and speed through solid-phase and liquid-phase amplification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional PCR devices are used with large reaction volumes (20-50 μL), then the thermal capacity is sufficient for stable reactions, but the heating and cooling ramp rates are inefficient, resulting in long amplification times (1-4 hours)
Solution Approach 1:
The device divides the heating system into two separate heating zones with independent temperature control, allowing simultaneous denaturation and annealing/extension reactions to occur in parallel. This segmentation enables faster thermal cycling by eliminating the need to sequentially heat and cool a single large reaction volume.
Solution Approach 2:
The invention transitions from a single vertical heating block to a horizontal microfluidic channel system where samples flow through different temperature zones. This dimensional change allows continuous thermal cycling through fluid movement rather than repeated heating and cooling of a stationary sample.
2Productivity
If microfluidic devices are used to reduce reaction volume and increase ramping rates, then amplification speed improves, but sensitivity is reduced due to smaller sample volume and fewer nucleic acid templates
Solution Approach 1:
The device combines multiple PCR reactions (denaturation and annealing/extension) into a single integrated microfluidic system with two heating zones. This merging allows parallel processing of multiple reactions with small sample volumes while maintaining sufficient sensitivity through the combined signal from all reactions.
Solution Approach 2:
The invention changes the temperature parameter distribution by creating two distinct heating zones with different constant temperatures, allowing optimal conditions for both denaturation and annealing/extension to occur simultaneously in different spatial locations within the microfluidic channel.
3Device complexity
If a single heating zone with changing temperature is used, then device complexity is reduced, but temperature changes take a long time, preventing rapid PCR
Solution Approach 1:
The heating system is segmented into two independent zones, each maintaining a constant optimal temperature for its specific function. This segmentation eliminates the time required to ramp temperatures up and down, as each zone continuously maintains its set temperature and samples are moved through them via fluid flow.
4Productivity
If multiple heating zones with fixed temperatures are used to enable rapid thermal cycling, then amplification speed increases, but the number of components and system complexity increases
Solution Approach 1:
The device merges the functions of multiple temperature control systems into a single microfluidic platform with two heating zones. By combining sample preparation, denaturation, and annealing/extension in one integrated system with controlled fluid flow, the complexity of managing multiple separate devices is reduced while maintaining rapid amplification capability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device achieves ultrafast nucleic acid amplification with increased sensitivity, reducing the number of cycles needed for detection and enabling rapid clinical testing.
Implementation Method 1
a heating plate comprising two heating zones at constant temperature
Implementation Method 2
moving the sample between these zones, enhancing sensitivity and speed through solid-phase and liquid-phase amplification
Data Source
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AI summary
The present invention concerns a microfluidic device for rapid amplification of target nucleic acids comprising (a) a microfluidic chip comprising at least one flow channel comprising a sample compartment, optionally at least one washing compartment, optionally a reading compartment, and oligonucleotides grafted on a capture surface of the flow channel, (b) a heating plate comprising two heating zones at constant temperature, wherein the capture surface is aligned with the second heating zone, and wherein the microfluidic chip is positioned on the heating plate. It also concerns methods using the same.