Re: Perfect Focus

Posted by Michael Weber-4 on
URL: http://confocal-microscopy-list.275.s1.nabble.com/Perfect-Focus-tp1098084p1098217.html

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Scott,

there are certainly ways to work without a hardware autofocus system.
One main thing is to keep the temperature stable, since even small
temperature changes can cause big focus drifts. So a climate chamber
around your whole system, plus a stable room air condition 24/7 is
necessary. This already gives a good and stable base for long term
experiments.

Such a hardware autofocus system makes things a bit more easy. It keeps
the coverslip or the bottom of your well plage in a constant position,
even if the temperature changes or the bottom is not even, due to a
slightly tilted stage or something like that.
There are a couple of limitations to these systems:
- speed of correction (some work parallel to the imaging, some don't)
- correction range is limited, so they don't correct over millimeters
- they don't work with all setups, you need a clear interference between
coverslip and water which acts as a mirror

If the major application will be long term time lapse, I definitely
recommend to have a closer look at the available systems.

Maybe this helps.

Michael


Scott Howell wrote:

> Search the CONFOCAL archive at
> http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
> All,
>
> Have new faculty coming aboard and a major application will be 48 hour
> timelapse studies in 96 well plates using multichannel collections.
> Therefore my question is how critical is it to have a system that has
> a perfect focus mechanism to meet this application? Are there decent
> work arounds if the perfect focus is not used? Have never actually
> worked with this type of system so would like input on this matter
> from the list. Thanks.  
>
>
> Scott J. Howell, Ph.D.
> Manager, Imaging Module
> Visual Sciences Research Center
> Case Western Reserve University
> 2085 Adelbert Rd.
> Institute of Pathology Room 106
> Cleveland, Ohio 44106
> 216-368-2300
> http://www.case.edu/med/vsrc