Posted by
Steffen Dietzel on
URL: http://confocal-microscopy-list.275.s1.nabble.com/why-does-high-NA-excitation-illumination-give-better-resolution-in-fluorescence-microscopy-tp7581519p7581526.html
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Am 03.02.2014 18:39, schrieb Reto Fiolka:
> I have seen many papers where people employed high NA oil objectives for
> confocal imaging in biological samples. Besides not being indexed matched, they
> will not provide more resolution, as any illumination above the critical angle is
> lost in the near field (critical angle for n=1.33 is reached at NA 1.33).
Well, NA 1.33 does sound like better resolution than the NA 1.2 of the
best Water-Coverslip-Objectives, does it not?
And just for the fun of it, if cells grow directly on the coverslip, n
is somewhat larger than 1.33 since you stay inside the cell for the
important parts of the image. (not that I would expect this to make a
big difference though)
Steffen
--
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Steffen Dietzel, PD Dr. rer. nat
Ludwig-Maximilians-Universität München
Walter-Brendel-Zentrum für experimentelle Medizin (WBex)
Head of light microscopy
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