Controlling the Retention of Small Molecules in Emulsion Microdroplets for Use in Cell-Based Assays
Controlling the Retention of Small Molecules in Emulsion Microdroplets for Use in Cell-Based Assays
复制标题
DOI：
10.1021/ac802658n
复制
发表时间：
2009-04-15
影响因子：
7.4
通讯作者：
Abell, Chris
中科院分区：
文献类型：
--
作者：
Courtois, Fabienne;Olguin, Luis F.;Abell, Chris
微流体中的油包水微滴是定义明确的单个皮升反应室，因此具有定量高通量生物筛选的巨大潜力。然而，这取决于液滴的内容不泄漏到油相中。为了评估可能的泄漏机制，研究了矿物油中形成的液滴中各种荧光素衍生物的保留情况，并在芯片上的储存器中储存了数小时。观察到泄漏到油相的情况，并证明泄漏取决于化合物的性质和所使用的硅基聚合物表面活性剂Abil EM 90的浓度。在将填充荧光素的液滴与仅填充缓冲液的液滴混合的实验中，从填充的液滴到空液滴的射流速率取决于相邻不同组成的液滴的数量。含有五个含荧光素邻居的缓冲液滴比没有荧光素邻居的缓冲液滴吸收荧光团的速度快4.5倍。添加牛血清白蛋白（BSA）大大减少泄漏。含有5% BSA的配方可将荧光团的泄漏率从45%降至3%。加入牛血清白蛋白后，实验可进行长达18小时，而不会出现大量泄漏(
Water-in-oil microdroplets in microfluidics are well-defined individual picoliter reaction compartments and, as such, have great potential for quantitative high-throughput biological screening. This, however, depends upon contents of the droplets not leaking out into the oil phase. To assess the mechanism of possible leaking, the retention of various fluorescein derivatives from droplets formed in mineral oil and stored for hours in a reservoir on chip was studied. Leaking into the oil phase was observed and was shown to be dependent on the nature of the compounds and on the concentration of the silicone-based polymeric surfactant Abil EM 90 used. In experiments in which droplets filled with fluorescein were mixed with droplets filled with only buffer, the rate of efflux from filled droplets to empty droplets was dependent on the number of neighboring droplets of different composition. Buffer droplets with five fluorescein-containing neighbors took up the fluorophore 4.5 times faster than buffer droplets without fluorescein neighbors. The addition of bovine serum albumin (BSA) substantially reduced leaking. A formulation with 5% BSA reduces leaking of the fluorophore from 45% to 3%. Inclusion of BSA enabled experiments to be carried out over periods up to 18 h, without substantial leaking (