Most fluorescence fluctuation experiments use a stationary laser beam to illuminate a small sample volume and analyze the temporal behavior of the fluorescence fluctuations within the stationary observation volume. Scanning of the laser beam in a circular pattern collects the fluorescence signal from a moving observation volume. The fluctuations contain now information about temporal and spatial properties of the sample. Synchronization between beam scanning and data collection allows us to evaluate the fluctuations for every position along the scanned trajectory. We present the theory of position-sensitive scanning fluorescence fluctuation spectroscopy and experimentally verify the theory. This technique is useful for detecting and characterizing directed transport processes in the presence of diffusion.
|Original language||English (US)|
|Number of pages||10|
|Journal||Progress in Biomedical Optics and Imaging - Proceedings of SPIE|
|State||Published - 2005|
|Event||Multiphoton Microscopy in the Biomedical Sciences V - San Jose, CA, United States|
Duration: Jan 23 2005 → Jan 25 2005
Bibliographical noteFunding Information:
This work was supported by grants from the National Institutes of Health (GM64589) and the National Science Foundation (PHY-0346782). Y.C. acknowledges support from a postdoctoral fellowship from the National Institutes of Health (GM020853).
- Fluorescence correlation spectroscopy
- Fluorescence fluctuation spectroscopy
- Scanning microscopy
- Transport processes
- Two-photon microscopy