|
Sources and Remedies
of Photodamage in Live Cell Microscopy
Hockberger, Philip1
Northwestern University Medical School1
Abstract-
During the twentieth century there was unprecedented progress in efforts
to understand the behavior and function of biological cells. Progress
during the past decade was accelerated by the development of new microscopic
imaging techniques and fluorescent dyes that allowed investigators to
visualize dynamic events within living systems. While these developments
led, and will continue to lead, to exciting new discoveries in cellular
and molecular biology, such studies are not without problems. One of
the most vexing is photodamage induced by illumination of cells (endogenous
toxicity) and dyes which are used to enhance the appearance of cells
(exogenous toxicity). The rate of photodamage imposes limits on how
long one can observe cells before the damage becomes apparent. A more
insidious problem is that photodamage can often influence cellular functions
even before it is apparent, e.g., by inducing early events in apoptosis.
The latter is often overlooked in microscopic studies of living cells
and tissues, and it is exacerbated by our incomplete understanding of
the causes and consequences of photodamage. This presentation will address
research aimed at understanding the main types of photodamage encountered
in live cell microscopy (endogenous and exogenous toxicities). I will
present examples of damage induced by different light sources and dyes,
and discuss contemporary ideas regarding the underlying causes of damage
including the generation of toxic photoproducts and reactive oxygen
molecules. I will also describe recent efforts aimed at reducing the
causes of photodamage during live cell microscopy. (also see, P. Hockberger,
Sources and Remedies of Phototoxicity in Live Cell Microscopy, Microscopy
Today, volume #00-4, pp. 30-32, 2000.)
Keywords: photodamage,
phototoxicity, microscopy, reactive oxygen molecules
|
