Re: Trying to image Cy7.5 -- AxioObserver.Z1 blocking IR?

Posted by Steffen Dietzel on
URL: http://confocal-microscopy-list.275.s1.nabble.com/Trying-to-image-Cy7-5-AxioObserver-Z1-blocking-IR-tp7586976p7586983.html

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
Post images on http://www.imgur.com and include the link in your posting.
*****

and if everything else should fail, you could try to couple the LED
fiber through the condenser into the light path and do transmission
fluorescence, as in the old days before the Ploem pak was invented in
the 60ies, at least for testing purposes.

But be careful: one of the major advantages of Epifluorescence is lost,
and that is usage safety: if you look into the light source through the
eye piece without appropriate filters in the beam path you may very well
damage your eyes. With above 700 nm, possibly you might not even notice
it at first. I am not sure how much damage 'unvisible' red light might do.

Steffen


Am 12.07.2017 um 07:18 schrieb Benjamin E Smith:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> Post images on http://www.imgur.com and include the link in your posting.
> *****
>
> As others have pointed out, the strong 700 nm cutoff sounds very much like
> a hot-mirror somewhere in the path, as that is a very common cut-off for
> hot mirrors:
> https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=6108
> https://www.edmundoptics.com/optics/optical-mirrors/specialty-mirrors/hot-mirrors/#resources
> https://www.chroma.com/products/parts/hot-mirror-26mm-50mm
>
> The hot mirror should be close to the light entry port on the microscope.
> Some microscopes allow the mirror to be flipped out with a lever, while on
> others it has to be physically removed.  A Zeiss rep should know exactly
> where it is in the path.
>
> Good luck,
>     Ben Smith
>
>
> On Tue, Jul 11, 2017 at 7:30 PM, <[hidden email]> wrote:
>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> Post images on http://www.imgur.com and include the link in your posting.
>> *****
>>
>> Hi Michael,
>> if you get the same readings before the filter cube (i.e. with the filter
>> turret removed), then there might be an IR blocking (heat blocking) filter
>> somewhere in the illumination part.
>>
>> According to this drawing
>>
>> http://www.zebrasc.com/Article.asp?pageclass=10201
>>
>> there is quite a number of elements in the light path. It could also be the
>> AR coating of the lenses (e.g Thorlabs VIS coating reflects up to 5% per
>> surface at 800nm), but the dramatic loss of intensity looks more like an
>> intentional IR blocking. Zeiss reps will know more...
>> Good luck!
>>
>> zdenek
>> --
>> Zdenek Svindrych, Ph.D.
>> W.M. Keck Center for Cellular Imaging (PLSB 003)
>> Department of Biology,University of Virginia
>> 409 McCormick Rd, Charlottesville, VA-22904
>> http://www.kcci.virginia.edu/
>> [hidden email]
>>
>> ---------- Původní e-mail ----------
>> Od: Cammer, Michael <[hidden email]>
>> Komu: [hidden email]
>> Datum: 11. 7. 2017 22:01:28
>> Předmět: Trying to image Cy7.5 -- AxioObserver.Z1 blocking IR?
>> "*****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> Post images on http://www.imgur.com and include the link in your posting.
>> *****
>>
>> A few weeks ago we asked about finding a light source at 780ish nm for
>> exciting Cy7.5. As always, people on this listserv provided very helpful
>> suggestions. We were able to get a pE-4000 system with multiple LEDs but
>> are
>> finding that the Zeiss AxioObserver.Z1 fluorescence illumination optics
>> appear to be cutting wavelengths above 700 nm.
>>
>> We adjusted the LED powers such that 635, 660, 740, and 770 nm all have 52
>> mW at the end of the liquid light guide. We removed the IR filter for the
>> autofocus system that is in the objectives nosepiece. However, the light at
>> 740 and 770 nm is blocked from arriving at the objective lenses.
>>
>> Does anyone know whether there is a filter somewhere else in the light path
>> we could easily remove to pass these wavelengths or is this a limitation of
>> the light train?
>>
>> (graphs of the power loss posted at http://microscopynotes.com/
>> axioobserver/
>> IR/ )
>> Thank you!!
>>
>> =*===========================================================*=
>> Michael Cammer, DART Microscopy Laboratory, NYU Langone Medical Center
>> Cell: 914-309-3270 (this is for calling, not texting) Office: Skirball 2nd
>> Floor main office, back right
>> http://ocs.med.nyu.edu/microscopy & http://microscopynotes.com/
>>
>>
>>
>> ------------------------------------------------------------
>> This email message, including any attachments, is for the sole use of the
>> intended recipient(s) and may contain information that is proprietary,
>> confidential, and exempt from disclosure under applicable law. Any
>> unauthorized review, use, disclosure, or distribution is prohibited. If you
>> have received this email in error please notify the sender by return email
>> and delete the original message. Please note, the recipient should check
>> this email and any attachments for the presence of viruses. The
>> organization
>> accepts no liability for any damage caused by any virus transmitted by this
>> email.
>> =================================
>> "
>>
>
>
--
------------------------------------------------------------
Steffen Dietzel, PD Dr. rer. nat
Ludwig-Maximilians-Universität München
Biomedical Center (BMC)
Head of the Core Facility Bioimaging

Großhaderner Straße 9
D-82152 Planegg-Martinsried
Germany

http://www.bioimaging.bmc.med.uni-muenchen.de