Highly Efficient Single Cell Capturing Using Hydrodynamic Guiding Structures

A microfluidic chip array for high-throughput single cell assay with an efficient cell capture rate was presented. The single cell capture structure utilizes hydrodynamic resistance difference in flow paths and its feasibility was tested. More than 40% of all the injected microbeads were captured in the designated capture sites. The capture structure was expanded in an array of microwells formed at the intersection of rows and columns of orthogonal microchannels. By selectively operating integrated pneumatic valves, we successfully demonstrated cell seeding, reagents injection and cell isolation without cross-contamination.

There have been growing interests in single-cell assay and a few groups have reported the microfluidic chips that incorporate single-cell capturing schemes. However, their capturing efficiency (the ratio of the total captured cells to the injected cells) is relatively poor (less than a few %) and may not be adequate for handling rare cells such as stem cells or cancer cells. In this paper we propose a highly efficient hydrodynamic capture scheme which can be applied to microfluidic array chips for different reagent injection and cell isolation. Using this scheme, we can load single cells into each microwell and simultaneously apply different reagents for various single-cell assays.

Figure 1: Photograph of the fabricated microarray chip. There are total 64 microwells in an array of 8mm x 8mm. (B) Photograph of the drug injection test: 4 different drugs are injected along every two rows and each row was isolated by closing the valves to prevent cross-contamination. (C) Photography of microwell isolation test: all the valves were closed during isolation operation. (D) Photograph of single cell capture test for PC3 prostate cancer cell. (E) Photograph of the PC3 after 3 days culture in the same microwell

Experimental Results - Movie

Related Publication
  1. J. Chung, Y.-J. Kim, I.-J. Cho, and E. Yoon, "Highly Efficient Single Cell Capturing in Microwell Array Using Hydrodynamic Guiding Structures," Micro Total Analysis Systems (mTAS'08), pp. 477-479, Oct. 2008.