以液介電泳原理開發應用於DNA分析之新式毛細管電泳晶片

Abstract

近年來毛細管電泳晶片發展十分快速，並且在DNA的分析測試上扮演重要角色。但目前毛細管電泳晶片皆封閉式流道架構，尚無開放式流道，開放式流道優點為製程簡易、可整合數位流體式晶片，如聚合脢連鎖反應數位流體晶片；因此本論文目的為嘗試利用液介電泳原理創造出開放式液體流道，藉由開放式流道進行毛細管電泳之進樣、分離與偵測。 藉由液介電泳電極設計，在100 kHz，100 V此特殊頻率之交流電場下，可將液體限制在液介電泳電極上方之垂直交流電場附近，而使緩衝液形成一開放式流道，並使用螢光物質(FITC)觀察到在兩側施加一直流電場時，液體出現電滲流之流動行為。利用分段式進樣與螢光偵測的方式，可在毛細管電泳之直流電場26.6 V/cm下，初步將三種不同片段長度(3 kb、5 kb、8 kb)之DNA進行進樣、分離與偵測。實驗中嘗試使用十字型、數位式以及分段式三種不同進樣方式，以及測試不同介電層材料，目標為達到以開放式流道為架構之新式毛細管電泳晶片。

Capillary electrophoresis (CE) microchip has played an important role in DNA analysis in recent years. However, all CE microchips nowadays are builted by close channel. We have developed a novel capillary electrophoresis microchip by an open channel technique without channel walls. The open channel here is created by utilizing liquid dielectrophoresis (LDEP) principle to confine liquids above the LDEP electrodes and form a open channel around the vertical AC electric field at 100 kHz, 100 V. While we applied a parallel DC electric field, electroosmotic flow (EOF) was observed by FITC doping in buffer solution. The device has demonstrated injection, separation and detection of DNA between two parallel plates. The sample can be transported by electroosmotic flow at parallel DC electric field. DNA was preliminary analyzed at DC electric field with amplitude of 26.6 V/cm in an open channel micro CE chip by fluorescence microscope.