- 2:40 PM

Using Antibody-Modified Microelectrodes for Capture and Release of Cells

He Zhu, Jun Yan, and Alexander Revzin. Department of Biomedical Engineering, University of California at Davis, 451 East Health Sciences Dr., Davis, CA 95616

The present study sought to design a novel strategy for releasing antibody-bound cells through electrochemical disruption of the underlying antibody (Ab) layer. Poly (ethylene glycol) (PEG) hydrogel photolithography was employed to make the glass regions non-fouling, thus, ensuring selective localization of proteins and cells on the microelectrodes. The gold surfaces were decorated with anti-CD4 Ab molecules using standard alkanethiol self-assembly and carbodiimide coupling approaches. The Ab-functionalized electrodes selectively captured model T-lymphocytes (Molt-3 cells) expressing CD4 antigen while minimal cell adhesion was observed on PEG hydrogel-modified glass substrates. Importantly, application of a reductive potential (-1.2 V vs. Ag/AgCl reference electrode) resulted in release of surface-bound T-cells from the electrode surface. In the future, the cell sorting approach described here may be combined with microfluidic delivery to enable Ab-mediated capture of T-lymphocytes or other cell types followed by release of select cells for downstream gene expression studies or re-cultivation.