UC San Diego

Optical tweezers and laser scissors are invaluable tools to manipulate cells on the micro and nano scale level. By integrating laser technologies with imaging and biochemical techniques, robust systems can be created to study various biological and biochemical processes. The purpose of this thesis is to describe two different optical methods used to study two cell-based problems. In the first experiment, optical tweezers are used to examine the effects of viscosity on sperm motility and energetics using a 1064nm Nd:YVO₄ continuous laser. In the second experiment, laser scissors are used to study growth cone response from laser induced damage using a Vanguard Nd: YVO₄ second harmonic generator (SHG) 532 nm picosecond green laser. The proceeding sections describe the optical systems for each experiment as well as the methods used. Results of both studies are presented and discussed in detail