Single cell scraper based on an Atomic Force Microscope

Abstract

Atomic Force Microscope (AFM) can be used in various environment such as atmosphere, vacuum and liquid. In the field of biology, AFM has been used to observe biological samples in liquid. AFM can be used not only for surface observation but also for local surface manipulation. Nano manipulation using AFM has attracted much attention in recent years. The typical manipulation techniques using AFM are directly scratching some samples on surfaces with the probe. However, it is difficult to control precise positioning of the probe edge at exact target on the sample. Recently, we have developed a compact AFM manipulator coupled with an inverted optical microscope to observe the AFM probe edge for accurate probe positioning and monitoring the scene of the manipulation. In this research, the AFM manipulator was customized to remove a single biological cell selectively from a substrate. To avoid damaging the cell, a micro-cell scraper was fabricated from a micro cantilever using a focused ion beam milling. As a demonstration, a single HeLa cell was selectively removed from the substrate, and then it was collected by a micropipette. The system would be very useful as a single cell sorter.