DNA分子在漸縮微渠道中流動的拉伸及動態特性

Abstract

本論文探討DNA分子於流動中之拉伸及動態特性，在實驗設計中，我們使用漸縮渠道，渠道包含儲液槽、漸縮段及直管，當流體經過漸縮段時，藉由截面積的變化而在渠道中心產生伸長流(Elongational flows)，研究中我們利用半導體製程技術製作實驗所須使用的渠道，並利用倒立式螢光顯微鏡及影像拍攝器，建立DNA分子的可視化技術，藉由改變DNA溶液的流量、黏滯係數進行實際觀測與分析DNA分子在伸長流下分子拉伸形態的改變及應力鬆弛現象，最後，結合前述的實驗結果，探討流動作用於DNA分子上的拉伸力。探討此物理特性，應可改善以DNA為主的微液生物晶片之生化反應效率，亦有助於了解DNA分子在流動下形態的穩定性及檢測的準確性。

This research purposes to investigate the stretching and immobilization behaviors of the lambda-DNA molecules during flow through a channel. After considering existing design, a convergent channel is adopted. The flow path consisted of an inlet reservoir, convergent channel and straight channel. Because of the variation of cross section, the flow experienced an elongational flow at the convergent channel along the channel centerline. We utilize semiconductor fabrication process to manufacture the micro-channel for experiment. Besides, we also build up the DNA visualization technology with fluorescent dye. The epifluorescence microscopy and image intensifier CCD camera was used. We observe the stretching and stress relaxation phenomena in the elongational flow at various values of flow rate and viscosity of DNA solution. We also calculate the stretching force acting on the DNA molecules by flow. It is important to understand these physical characteristics for improving the efficiency of biochemical reaction in micro fluidic devices. This analysis is also instrumental for understanding the stability of DNA molecules and for ensuring accuracy of DNA sample detection in fluid flows.