The Role of Mitochondria in the detection of Infrared Light Sources by Mammalian Cells.
Abstract
If biological materials absorb specifically in the near infrared it is likely that they use some of the quantum energy for structural and other changes of the absorbing molecules and, thus, re-emit light of lesser quantum energy. In other words, one may expect that they fluoresce in the near infrared if exposed to near infrared light. The fluorescence, in turn, is likely to reflect functionally important structural properties of the light sensing and processing materials. (1) We tested this conjecture by developing a near infrared fluorescence microscope. As a first application of this microscope we report that Rhodospirillum rubrum, a species of purple bacteria, autofluoresce in the near infrared and offer evidence that the autofluorescent material is bacteriochlorophyll. By comparing the autofluorescence of live and fixed bacteria we suggest that the bacteria regenerate their chlorophyll with a time constant of approximately 20 s. In the future we will applay the new microscope to study the autofluorescence of mitochondria. (2) The movements of mitochondria have been linked to microtubules. We tested whether we can detect signals that travel along microtubules in cells irradiated with pulsating near-infrared light. We found, indeed, that under these conditions an unknown type of signals travels to the plus end of microtubules in cells and destabilizes them temporarily.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 08, 2000
- Accession Number
- ADA376002
Entities
People
- Guenter Albrecht-buehler
- Robert L. Rea
Organizations
- Northwestern University