Microtubules are filament-shaped, polymeric proteins (~25 nm in diameter) involved in cellular structure and organization. We demonstrate the imaging of individual microtubules using a conventional bright-field microscope, without any additional phase or polarization optics. Light scattered by microtubules is discriminated through extensive use of digital image-processing, thus removing background, reducing noise and enhancing contrast. The setup builds on a commercial microscope, with the inclusion of a minimal and inexpensive set of components, suitable for implementation in the student laboratory. We show how this technique can be applied to a demonstrative biophysical assay, by tracking the motions of microtubules driven by the motor protein kinesin.
@article{arxiv.0911.1490,
title = {Visualizing individual microtubules using bright-field microscopy},
author = {Braulio Gutiérrez-Medina and Steven M. Block},
journal= {arXiv preprint arXiv:0911.1490},
year = {2015}
}