應用於數位微流體生物晶片中達到反應物及廢液最小化之多目標濃度樣本製備程序

Abstract

樣本製備程序(sample preparation)為各種生化反應中不可或缺的步驟。原始生物樣本或反應試劑必須在此程序中進行稀釋或混合，以達到反應所需的目標濃度(target concentration)。一般來說，一個生化反應通常需要某一樣本的多重目標濃度。但是，大部分現有的樣本製備程序規劃相關演算法，都是針對單一目標濃度的製備而設計。因此，當需要製備多目標濃度時，會採用依序製備的方式，這種方式被認為較無效率與耗時。若所需的多目標濃度在此過程中可以同時製備，那麼稀釋/混合反應的次數與反應物的使用量都可以再降低。本篇論文提出一個廢液回收再利用的演算法，簡稱WARA，來解決在數位微流體生物晶片(digital microfluidic biochips, DMFBs)上，多目標濃度樣本製備程序規劃(multi-target sample preparation)的問題。WARA的主要概念為，將樣本製備程序中的副產物－廢液滴回收後再利用。藉由這個概念，反應物的使用量與廢液滴的生成量都可以大幅降低。實作上，WARA透過液滴共享與液滴置換的方法來回收廢液。實驗結果顯示，與現行成效最好的多目標濃度樣本製備程序演算法相比，當目標濃度數目為十的時候，WARA產生的廢液數量較其減少了48%，而所需要的稀釋/混合反應次數則減少了37%；當目標濃度數目持續增加，此降低程度更是顯著─最多可減少97%的廢液生成量與73%的稀釋/混和反應次數。

Sample preparation is an essential process in biochemical reactions. Raw reactants are diluted to reach the given target concentrations. Typically, a bioassay may require several different target concentrations of a reactant. However, most of existing algorithms are designed for single-target sample preparation only. When they are applied to prepare multiple target concentrations, these target concentrations are prepared separately one by one, which is inefficient and time-consuming. If all these target concentrations are produced simultaneously during sample preparation, both the dilution operation count and the reactant usage can be further minimized. In this thesis, we propose a waste recycling algorithm, WARA, to tackle the multi-target sample preparation problem on digital microfluidic biochips (DMFBs). The main idea of WARA is to recycle waste droplets in the dilution process and turn them into usable ones for reactant and waste minimization. WARA achieves waste recycling through droplet sharing and droplet replacement. Experimental results show that WARA can reduce the waste and operation count by 48% and 37% respectively as compared to an existing state-of-the-art multi-target sample preparation method when the number of target concentrations is ten. The reduction can be up to 97% and 73% when the number of target concentrations goes even higher.