Can you control the nanoparticle with the laser, or is the laser only used to follow and track the particle?

Question: Can you control the nanoparticle with the laser, or is the laser only used to follow and track the particle?
- Keywords:
  control,
  how science works,
  laser,
  nanoparticle,
  particle
Asked by chemistry654 to Pip on 25 Jun 2012.
- Philippa Bird answered on 25 Jun 2012:
  
  You most certainly can control the nanoparticle with the laser – believe it or not that is actually easier to do than following and tracking the particle! (this is not used inside the human body, it is done in single cells on microscope slides.) What would you do inside cells with nanoparticles if you could control them?

Question: Can you control the nanoparticle with the laser, or is the laser only used to follow and track the particle?