Institute of Microanalytical Systems, Department of Chemistry, Zhejiang University, Hangzhou 310058, China.
Anal Chem. 2010 Dec 1;82(23):9941-7. doi: 10.1021/ac1020479. Epub 2010 Nov 2.
This paper describes DropLab, an automated microfluidic platform for programming droplet-based reactions and screening in the nanoliter range. DropLab can meter liquids with picoliter-scale precision, mix multiple components sequentially to assemble composite droplets, and perform screening reactions and assays in linear or two-dimensional droplet array with extremely low sample and reagent consumptions. A novel droplet generation approach based on the droplet assembling strategy was developed to produce multicomponent droplets in the nanoliter to picoliter range with high controllability on the size and composition of each droplet. The DropLab system was built using a short capillary with a tapered tip, a syringe pump with picoliter precision, and an automated liquid presenting system. The tapered capillary was used for precise liquid metering and mixing, droplet assembling, and droplet array storage. Two different liquid presenting systems were developed based on the slotted-vial array design and multiwell plate design to automatically present various samples, reagents, and oil to the capillary. Using the tapered-tip capillary and the picoliter-scale precision syringe pump, the minimum unit of the droplet volume in the present system reached ~20 pL. Without the need of complex microchannel networks, various droplets with different size (20 pL-25 nL), composition, and sequence were automatically assembled, aiming to multiple screening targets by simply adjusting the types, volumes, and mixing ratios of aspirated liquids on demand. The utility of DropLab was demonstrated in enzyme inhibition assays, protein crystallization screening, and identification of trace reducible carbohydrates.
本文介绍了 DropLab，这是一种自动化的微流控平台，用于在纳升级别上编程液滴反应和筛选。DropLab 可以以皮升级别（picoliter-scale）的精度计量液体，顺序混合多种成分以组装复合液滴，并以极低的样品和试剂消耗在线性或二维液滴阵列中进行筛选反应和分析。本文开发了一种基于液滴组装策略的新型液滴生成方法，可在纳升级别至皮升级别范围内生成多组分液滴，并且每个液滴的尺寸和组成具有高度可控性。DropLab 系统使用带有锥形尖端的短毛细管、皮升级别精度的注射器泵和自动化液体呈现系统构建而成。锥形毛细管用于精确计量和混合液体、液滴组装以及液滴阵列存储。基于插槽瓶阵列设计和多井板设计开发了两种不同的液体呈现系统，用于自动向毛细管呈现各种样品、试剂和油。使用锥形尖端毛细管和皮升级别精度的注射器泵，本系统中液滴体积的最小单元达到约 20 pL。无需复杂的微流控网络，各种不同尺寸（20 pL-25 nL）、组成和顺序的液滴可以自动组装，通过简单地按需调整吸入液体的类型、体积和混合比，即可针对多个筛选目标进行操作。DropLab 的实用性在酶抑制测定、蛋白质结晶筛选和痕量可还原碳水化合物的鉴定中得到了验证。
