SEQUENTIAL SCREENING SERIAL

Md Rifat Hassan, Jie Zhang, Cheng Wang.Counting Protein Number in a Single Cell by a Picoliter Liquid Operating Technology. Hailong Yu, Qunfei Tai, Chenjie Yang, Lingxiao Weng, Mingxia Gao, Xiangmin Zhang.This article is cited by 64 publications.

SEQUENTIAL SCREENING SERIAL

The ability of the SODA system in performing complicated and multistep droplet manipulations was further demonstrated in the serial dilution of nanoliter-scale inhibitor droplets with concentrations spanning 6 orders of magnitude for IC 50 profiling, which includes droplet generation, indexing, splitting, transferring, and fusion with picoliter precision. In the experiments, the consumptions of samples and reagents are only 60–180 pL for each droplet microreactor, which are commonly 3–5 orders of magnitude lower than those of conventional multiwell plate systems, and 1–2 orders of magnitude lower than other droplet-based microfluidic systems for multiple sample screening. To demonstrate its feasibility and versatility, we applied the SODA system in multiple experiments required in drug screening, including the screening of inhibitors for capases-1 from a chemical library, the measurement of IC 50 values for the identified inhibitors, and the screening of the synergistic effect of multiple inhibitors. Differing from the previously reported droplet systems based on microchips, microcapillaries, or digital microfluidics, this method can achieve complete and flexible droplet manipulations, including droplet assembling, generation, indexing, transferring, splitting, and fusion in the picoliter range, endowing the present system with ultralow sample/reagent consumptions and substantial versatility in analysis and screening for multiple different samples. On this basis, an automated droplet manipulation method with picoliter precision was established using the programmable combination of the capillary-based liquid aspirating–depositing and the moving of the oil-covered droplet array, the so-called “aspirating–depositing–moving” (ADM) method.

With the system, we developed a novel picoliter-scale droplet depositing technique for forming a 2D picoliter-droplet array. The SODA system was built using a tapered capillary-syringe pump module and a two-dimensional (2D) oil-covered droplet array installed on an x–y–z translation stage. This contribution describes a sequential operation droplet array (SODA) system, a fully automated droplet-based microfluidic system capable of performing picoliter-scale liquid manipulation, analysis, and screening.

Sequential screening