Multifunctional microwell plate for on-chip cell and microbead-based bioassays

This paper reports on a multifunctional microwell plate developed for lab-on-a-chip applications, such as high-throughput cell assay, drug screening, and microbead-based analyses. The proposed device was designed to provide three consecutive functions: the autonomous capture of biomaterials into multiple microwells in a two-dimensional array; active physical sealing of the microwells for isolation; and specific chemical injection into each microwell. The device was implemented with microfabrication technology using polydimethylsiloxane (PDMS) structures on a silicon or glass substrate. The multiple functions of the microwell plate were successfully demonstrated in an experiment using microbeads. The parallel positioning of live cells (CHO DG44) in multiple microwell arrays was achieved, as well as the independent injection of foreign solution into a specific target cell. Also the proposed microwell plate was utilized to capture microbeads, for antibody injection into each microwell, for quantum dot (QD) injection, and for fluorescence detection for a feasible demonstration of a microbead-based assay.