Re: Using Sapphire Cover Slip with a Confocal Microscope

From: Andy Resnick (andy.resnick_at_op.case.edu)
Date: 03/23/05 

Date: Wed, 23 Mar 2005 16:19:10 -0500

Philip wrote:

> <snip>
>>
>
> I planned to try it out with a 20x objective with a 3500 microns working
> distance. Depending on what we see (or don't see), we might purchase a
> lens with an even larger working distance.
>
> So will the conlusion change with say a 2 photon?

Let me premise this by stating I have never personally used a two photon
scope. But, a low NA lens (3.5 mm working distance, 20X... around 0.4,
0.5 maybe?)... I can't see how you are going to get the power density in
the sample high enough to excite a 2nd harmonic. At least not without
blasting the bejeezus out of the sample, and then I wonder what are
biological effects on your biological sample being held at high pressures?

I would suggest taking a step back- maybe microscopy is not the
appropriate tool for your job. Are there alternative ways of obtaining
the information? Spectroscopically? Non-imaging methods? Non-optical
methods?

A few minutes of thought and discussion in your group could potentially
save major dollars and timewasting. 

-- 
Andrew Resnick, Ph.D.
Department of Physiology and Biophysics
Case Western Reserve University