Visualizing individual microtubules using bright-field microscopy

TL;DR

This paper presents a simple, cost-effective bright-field microscopy method enhanced with digital image processing to visualize and track individual microtubules, enabling biophysical studies without specialized optics.

Contribution

It introduces a novel approach combining conventional microscopy with digital processing to visualize single microtubules, accessible for educational and research purposes.

Findings

Successful imaging of individual microtubules using standard microscopes.

Effective discrimination of microtubule light scattering through digital processing.

Application demonstrated by tracking kinesin-driven microtubule motion.

Abstract

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.