An experimental setup for combining optical tweezers and laser scalpels with advanced imaging techniques.

In this paper we will describe a system designed to combine optical tweezers and laser scalpels with confocal as well as epi-fluorescence microscopy. A continuos wave Nd:YVO4 laser is used to produce a dual optical tweezers, where each trap can be individually controlled. A second optical tweezers setup is based on a tunable titanium sapphire laser, which allows us to adjust the wavelength to minimize the damage to the cell under investigation. A pulsed nitrogen laser working at 337 nm forms a laser scalpel. The tweezers and scalpels are both incorporated in an inverted microscope equipped with epi-fluorescence and confocal imaging capabilities. In order to further control the sample we have developed a technique to tailor make the environment closest to the studied objects. Micrometer-sized structures such as channels and reservoirs have been produced in rubber silicon using lithographic methods. In combination with a micromanipulator, our system can be used to extract single cells from a population of billions for further studies or growth.