The Measurement Of Optical Force From Optical Tweezers And The Research On The Combination Of Optical Tweezers And Patch Clamp

Based on the introduction of optical tweezers,the main points of this dissertation are the measurement of optical force from optical tweezers with different microscope objectives,and the initial research of combination of optical tweezers and patch clamp aiming to research cell's electrical characteristics.The first chapter is the introduction of optical tweezers' history,main theory, characteristics,new developments,application and the combination of optical tweezers and other approaches used in research.The second chapter is the introduction of major optical elements of single beam gradient force laser optical trap and the different methods of position detection and force measurement.The third chapter is the measurement results of optical trapping force using LOTII optical tweezers-produced by Shanghai USTC LOT Technology CO.-based on the theory of thermal equilibrium.Through the comparison of the results from using 40X microscope objective with 0.65 numerical aperture and the 100X microscope objective with 1.25 numerical aperture,it shows that 100X microscope objective having bigger optical force not only in lateral direction but also in axial direction.In the same experiment condition,like incident laser power,trapped cell etc,the stiffness coefficient using 100X microscope objective is higher than that of 40X microscope objective.The higher trapping ability of 100X microscope objective shows in the aspects of the trapping efficiency is higher and the ability to restrict trapped cell's movement in the axial direction,and the fluency of manipulation of the trapped cell.According to this result,microscope objective with higher amplification and numerical aperture should be used in optical trapping research for the purpose of higher trapping efficiency and fluent manipulation.The forth chapter is the initial research of the combination of LOTII model optical tweezers and EPC-10 model patch clamp.The aim of this combination is to improve the research of the measurement of electrical characteristics of neuron cells.Through the experiment process,after optical tweezers trapping a cell,the micropipette of patch clamp approaches the cell and pushes the cell,but maintains the cell still in the optical trapping well. Use the stiffness coefficient to calculate the force carried out by the micropipette.The result is useful in the aspect of calibration of negative pressure from the negative pressure device.