Detection and Collection System of Target Single Cell Based on pH and Oxygen Sensing

This paper describes single-cell-based detection and collection using pH and oxygen sensing with microarrayed chemical sensors we developed previously to monitor single-cell activity in parallel. Such sensors consist of optical sensor film for pH or oxygen and microwell arrays prepared with carbon-black-doped polydimethylsiloxane (PDMS). We monitored single-cell respiration in parallel using a microarrayed oxygen sensor. An automatic single-cell collector we developed can be used with a commercial inverted microscope. The single-cell-based detection and collection we developed based on respiration or metabolic activity combines these two techniques. Model experiments for single-cell-based detection and collection based on metabolic activity used urease-immobilized microbeads (6 mu m i.d.). Fluorescence intensity after substrate injection increased only in wells containing urease-immobilized microbeads. Bead in target wells could be successfully collected alone, leaving other beads in their wells, by simply pushing a controller button, requiring no training or skill.