Optical trapping techniques involving microrheology and Tcell triggering

Abstract

Since their invention in 1970, optical traps have been used for a wide variety of applications including microrheolgy, dna stretching, as well as being a useful tool for gaining insight on the mechanics of molecular motors. In this thesis, an optical trap was used to determine the properties of both a Newtonian and a non-Newtonian fluid. A glycerol/water mixture was tested ranging from 0 weight percent to 95 weight percent glycerol. The data gathered from the optical trap agreed with results previously published using a rheometer. Xanthan gum was mixed with water ranging from 0.01 weight percent to 0.1 weight percent and tested. The data gathered from the trap matched the results given by the manufacture.

Tcells were triggered by using an optical trap to apply force upon the Tcell receptor. Oscillatory force along with a step and hold force both were used for the triggering. Oscillatory force required only 5 minutes to trigger while the step and hold approach took over 25 minutes.