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Title: A surface-coupled optical trap with 1-bp precision via active stabilization
Optical traps can measure bead motions with Å-scale precision. However, using this level of precision to infer 1-bp motion of molecular motors along DNA is difficult, since a variety of noise sources degrade instrumental stability. In this chapter, we detail how to improve instrumental stability by (1) minimizing laser pointing, mode, polarization, and intensity noise using an acousto-optical-modulator mediated feedback loop and (2) minimizing sample motion relative to the optical trap using a three-axis piezo-electric-stage mediated feedback loop. These active techniques play a critical role in achieving a surface stability of 1 Å in 3D over tens of seconds and a 1-bp stability and precision in a surface-coupled optical trap over a broad bandwidth (Δf = 0.03–2 Hz) at low force (6 pN). These active stabilization techniques can also aid other biophysical assays that would benefit from improved laser stability and/or Å-scale sample stability, such as atomic force microscopy and super-resolution imaging.  more » « less
Award ID(s):
1734006
PAR ID:
10057232
Author(s) / Creator(s):
Date Published:
Journal Name:
Methods in molecular biology
Volume:
1486
ISSN:
1064-3745
Page Range / eLocation ID:
77-107
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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