Deformation of single cells - optical two-beam traps and more

摘要

An optical two-beam trap composed from two counter propagating laser beams is an interesting setup due to theability of the system to trap, hold, and stretch soft biological objects like vesicles or single cells. Because of thisfunctionality, the system was also named the optical stretcher by Jochen Guck, Josep Kas and co-workers almost20 years ago (J. Guck et al, Biophys. J. 81, 767 (2001)). In a favorable setup, the two opposing laser beamsmeet with equal intensities in the middle of a uidic channel in which cells may ow past, be trapped, stretched,and allowed to move on, giving the promise of a high throughput device. Yet, single beam optical traps, akaoptical tweezers, by far outnumber the existing optical stretchers in research labs throughout the world. Theability to easily construct an optical stretcher setup in a low-cost material would possibly imply more frequentuse of the optical stretching technique. Here, we discuss advantages and disadvantages of choice of materialand methodology for chip assembly and chip production. For high throughput investigations of stretchingdeformation of single cells, optical stretching is, however, out-performed by hydrodynamic deformability assays.As we will discuss, injection molded polymer chips may with advantage be applied both for optical stretchingand for hydrodynamic deformability experiments.