Chemical cytometry on a picoliter-scale integrated microfluidic chip.
An integrated microfluidic device has been fabricated for analyzing the chemical contents of a single cell (chemical cytometry). The device is designed to accomplish four different functions: (i) cell handling, (ii) metering and delivering of chemical reagents, (iii) cell lysis and chemical derivatization, and (iv) separating derivatized compounds and detecting them by laser-induced fluorescence. These functions are accomplished with only two valves, formed by multilayer soft lithography. A new kind of three-state valve and a picopipette are described; these elements are crucial for minimizing the reaction volume and ensuring optimal shape of the channel for electrophoresis injection. By using these valves, a reaction volume of approximately 70 pl is achieved for the lysis and derivitization of the contents of a single Jurkat T cell (approximately 10 microm diameter). As a demonstration of the use of this integrated microfluidic device, electropherograms of amino acids from individual Jurkat T cells are recorded and compared with those collected from a multiple-cell homogenate.
Department of Chemistry, Stanford University, Stanford, CA 94305-5080, USA.
Hongkai
H
Wu
Aaron
A
Wheeler
Richard N
RN
Zare
D019075:Electrophoresis, Capillary; D005057:Eukaryotic Cells / Q000737:chemistry*; D006801:Humans; D019169:Jurkat Cells; D044085:Microfluidics / Q000295:instrumentation; D036103:Nanotechnology