Optical trapping inside living organisms

@inproceedings{citeulike:1409598, abstract = {We use optical tweezers to investigate processes happening inside living cells. In a previous study,1 we trapped naturally occurring lipid granules inside living yeast cells, and used them to probe the viscoelastic properties of the cytoplasm. However, we prefer to use probes which can be specifically attached to various organelles within the living cells in order to optically quantify the forces acting on these organelles. Therefore, we have chosen to use nanometer sized gold beads as probes. These gold beads can be conjugated and attached chemically to the organelles of interest. Only Rayleigh metallic particles can be optically trapped2 and for these it is the case that the larger the beads, the larger the forces which can be exerted and thus measured using optical tweezers.3 The gold nanoparticles are injected into the cytoplasm using micropipettes. The very rigid cell wall of the S. pombe yeast cells poses a serious obstacle to this injection. In order to be able to punch a hole in the cell, first, the cells have to be turned into protoplasts, where only a lipid bilayer separates the cytoplasm from the surrounding media. We show how to perform micropipette delivery into the protoplasts and also how the protoplasts can be ablated using the trapping laserlight. Finally, we demonstrate that we can transform the protoplasts back to normal yeast cells. Art. No.: 593003 Sponsors: SPIE \_ The International Society for Optical Engineering}, address = {Niels Bohr Institute, Blegdamsvej 17, 2100 Copenhagen, Denmark}, author = {Hansen, P. M. and Oddershede, L. B. and Spalding, G. C. and Dholakia, K. }, citeulike-article-id = {1409598}, doi = {10.1117/12.616879}, journal = {Proc SPIE Int Soc Opt Eng}, keywords = {tweezers}, pages = {1--9}, posted-at = {2008-05-16 19:32:18}, priority = {2}, series = {Optical Trapping and Optical Micromanipulation II}, title = {Optical trapping inside living organisms}, url = {http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal\&id=PSISDG005930000001593003000001\&idtype=cvips\&gifs=yes}, volume = {5930} }

TY - CONF ID - citeulike:1409598 L3 - citeulike-article-id:1409598 TI - Optical trapping inside living organisms SE - Optical Trapping and Optical Micromanipulation II JF - Proc SPIE Int Soc Opt Eng VL - 5930 SP - 1 EP - 9 AD - Niels Bohr Institute, Blegdamsvej 17, 2100 Copenhagen, Denmark N2 - We use optical tweezers to investigate processes happening inside living cells. In a previous study,1 we trapped naturally occurring lipid granules inside living yeast cells, and used them to probe the viscoelastic properties of the cytoplasm. However, we prefer to use probes which can be specifically attached to various organelles within the living cells in order to optically quantify the forces acting on these organelles. Therefore, we have chosen to use nanometer sized gold beads as probes. These gold beads can be conjugated and attached chemically to the organelles of interest. Only Rayleigh metallic particles can be optically trapped2 and for these it is the case that the larger the beads, the larger the forces which can be exerted and thus measured using optical tweezers.3 The gold nanoparticles are injected into the cytoplasm using micropipettes. The very rigid cell wall of the S. pombe yeast cells poses a serious obstacle to this injection. In order to be able to punch a hole in the cell, first, the cells have to be turned into protoplasts, where only a lipid bilayer separates the cytoplasm from the surrounding media. We show how to perform micropipette delivery into the protoplasts and also how the protoplasts can be ablated using the trapping laserlight. Finally, we demonstrate that we can transform the protoplasts back to normal yeast cells. Art. No.: 593003 Sponsors: SPIE _ The International Society for Optical Engineering KW - tweezers AU - Hansen, PM AU - Oddershede, LB AU - Spalding, GC AU - Dholakia, K UR - http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PSISDG005930000001593003000001&idtype=cvips&gifs=yes ER -