Pipette Tip Reciprocating Liquid Delivery in Detection Chips
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Solution Overview
Problem
Existing liquid delivery methods for microchannels in detection systems face challenges in preventing air from entering the microchannel during reciprocating liquid delivery, which can hinder the binding of detection target substances and reduce detection accuracy.
Innovation Solution
A method involving a pipette tip inserted into a liquid injection portion to create a hermetically sealed state, generating negative pressure to raise the liquid level, and controlling injection and aspiration to prevent air aspiration, ensuring air-free reciprocating delivery of liquids into the microchannel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If reciprocating delivery of liquid is performed by injection and aspiration using a pipette tip, then the contact between detection target substance and capture agent is increased, but air enters the microchannel together with the liquid
Solution Approach 1:
The pipette tip is preliminarily positioned to insert deeply into the liquid injection portion before liquid delivery begins. This preliminary positioning ensures that the tip remains submerged throughout the reciprocating delivery process, preventing air from being drawn into the microchannel while maintaining efficient liquid contact for target substance binding.
Solution Approach 2:
The liquid injection portion serves as an intermediary chamber between the external liquid source and the microchannel. By establishing a sealed environment in this intermediate space and maintaining liquid level above the pipette tip opening, the system mediates between the need for reciprocating delivery and the need to prevent air entry.
2Object-affected harmful factors
If the pipette tip is inserted deeply into the liquid injection portion, then air aspiration is suppressed, but the device complexity increases
Solution Approach 1:
The system uses the liquid itself to indicate the correct positioning of the pipette tip. By observing the liquid level in the injection portion, the operator can self-adjust the tip depth to be just below the liquid surface, eliminating the need for complex positioning mechanisms or additional sensors.
Solution Approach 2:
The detection chip with its integrated liquid injection portion is designed as a disposable component. This allows the use of simple, non-precise pipette tips without compromising overall system performance, as each chip is single-use. The complexity is shifted from the reusable pipette to the disposable chip structure.
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
This approach effectively suppresses air entry into the microchannel, enhancing the accuracy of detection target substance binding and detection processes by maintaining a sealed environment during liquid delivery.
Implementation Method 1
generating a negative pressure in the liquid injection portion (3101) to raise the level of the liquid (500)
Data Source
AI summary
Aiming to provide a method capable of reciprocatingly delivering various liquids without bringing air into a microchannel, a detection system and a detection apparatus for implementation of this method. In order to achieve at least one of the above aims, provided is a method of inserting a pipette tip into a liquid injection portion of a detection chip including: the microchannel; the liquid injection portion connected to one end of the microchannel; and a reservoir connected to the other end of the microchannel, injecting and aspirating the liquid by the pipette tip, and reciprocatingly delivering the liquid into the microchannel. At this time, the following steps are executed in this order, the steps including: inserting the pipette tip into the liquid injection portion up to a position at which an end of the pipette tip comes below a liquid level when the liquid is injected into the liquid injection portion; injecting the liquid from the pipette tip into the liquid injection portion; generating a negative pressure in the liquid injection portion to raise the level of the liquid in the liquid injection portion; and performing either aspiration of the liquid in the liquid injection portion by the pipette tip, or injection of the liquid into the liquid injection portion by the pipette tip and aspiration of the liquid inside the liquid injection portion.