FIG. 13.

Elongation of a single DNA molecule through the interaction between the microbead and the optical image. (a) A DNA molecule was treated with one end bound to a microbead and the other end with the substrate; (b) the generated negative ODEP force was employed to trap the microbead; (c) and (d) by moving the trapped microbead with the aid of computer software, a single DNA molecule was successfully stretched to a programmed position. Reproduced with permission from Lin et al., Opt. Express 17, 15318 (2009). Copyright 2009 OSA Publishing.