利用溫度梯度晶片系統構築微管聚合

Abstract

微管（MTs, or microtubules）在溫度梯度場下往單一方向進行聚合反應，這種環境與微管在軸突中的形成相似。因此，為了模擬這樣的環境，我們發展了一種具有加熱器、可以產生線性溫度梯度的微流體平台，這平台可以促使微管在晶片上進行聚合反應，並且控制其聚合方向。在實驗中，我們發現了微管在溫度梯度場中可以成功的聚合並整齊排列。同時，為了量化MT的排列情形，我們利用了以結構張量(structure tensor)的圖像處理技術。結果說明，在溫度梯度場下，微管排列集中在31.2度內的區間。相對應的，在均勻溫度場下，微管則廣泛分佈，較無方向性。 此外，我們研究在兩種不同的微管蛋白濃度下，微管的聚合情形與排列情況發現了，在高濃度環境下的微管聚合比在低濃度環境下的微管聚合，由於有較為足夠的微管蛋白濃度，微管聚合有著範圍較長的排列的距離。

Microtubules (MTs) were unidirectionally polymerized under a temperature gradient field - an environment which was similar to their formation in axon. We proposed a microfluidic platform with a triangular heater to generate a linear temperature gradient for on-chip MT polymerization. It was found that the MTs were polymerized and neatly aligned in the temperature gradient field. To quantify the alignment of MTs, an image processing technique based on structure-tensor were utilized. The results showed the MTs under the temperature gradient field had a better alignment within 31.2 degrees, whereas the MT under the uniform temperature field widely dispersed. Further, the MT polymerization and alignments at two different tubulin concentrations were examined. The MT polymerized at the higher concentration was aligned for a longer distance than the one at the lower concentration due to the sufficient tubulin concentration.