Re: super resolution - Zeiss enters the boat

Posted by Martin Wessendorf on
URL: http://confocal-microscopy-list.275.s1.nabble.com/coverslips-for-cell-culture-tp590595p590611.html

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Hey, Chris--

Chris Wood wrote:

> And it seems to me that STED will be suitable for live cells
> sooner than the PALM-STORM techniques.

Interesting question.  Someone pointed out to me off-list that with
STED, the fluorophore gets taken up to the excited state many more times
(--presumably 25x for a 5x increase in resolution) than with
conventional multiphoton microscopy for each photon of actual
fluorescence.  However, for each time it's in the excited state, it has
the same probability of bad photochemistry occuring--e.g., transition to
the triplet state and/or phototoxicity.  In this example, you'd expect
25x more phototoxicity with STED than with multiphoton in order to
obtain the same image.  Thus there may be inherent limitations with STED
with regards to live-cell imaging.

That being said, it'd appear that the weakness is relative: if you can
create a fluorophore that has a lower probability of engaging in bad
photochemistry, live-cell might be doable.  So it strikes me that (in
agreement with what other people have already pointed out) we'll
probably need new, better fluorophores to do live-cell imaging with STED.

Martin Wessendorf
--
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