Re: laser choices for multiphoton

Posted by Dr. K N Ganesh on
URL: http://confocal-microscopy-list.275.s1.nabble.com/laser-choices-for-multiphoton-tp7585404p7585417.html

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Try some of the IR corrected silicone immersion objectives (Super apo) They
have good transmission range upto 1600nm.
No commercial interests please.
Reg
Ganesh
On Jul 8, 2016 7:45 PM, "Steffen Dietzel" <[hidden email]> wrote:

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>
> Michael,
>
> you probably are aware that some red dyes do just nicely when excited
> around 860 or so, although is most likely not the S1-state (Mütze et al.,
> Excitation Spectra and Brightness Optimization of Two-Photon Excited
> Probes. doi:10.1016/j.bpj.2011.12.056)
>
> Having said that, I like the possibility to tune up to 1300 nm. It gives
> you much more flexibility. e.g. exciting Eosin is not a problem, or the red
> FPs. Also I like THG a lot, usually around 1275 nm excitation, with the THG
> signal at 425 nm and SHG at 638.
>
> So far we didn't have an application where we needed a high laser line
> (e.g. 1200) and a low one (850) simultaneously. If one comes around we
> would have to tune the laser, which takes time. If this is a frequent
> request at your site, you might be better of with two lasers. If money were
> no issue, I'd suggest two lasers tunable up to 1300nm...
>
> Our old LaVision BioTech and also our new Leica SP8 both support
> sequential scanning with several wavelengths (tuning in-between), I suppose
> the others do too.
>
> I believe the fixed 1046 is useful only if you want to do CARS. Or if you
> happen to have fluors that are nicely excited at that range. But I don't
> know any. In that respect a TiSa-OPO combination may be more useful were
> you can take out 10% of a 4 W laser to image directly (e.g.834 nm) and the
> 90% to generate a long wavelength.
>
> I wouldn't worry too much about cooking. One, the absorption of tissue is
> very low between 1200 and 1300. Two, the transmittance of the microscopes
> is very low, so you might get not so much out of the objective (still
> plenty to do fluorescence). Three, if you are still worried, a resonant
> scanner might be a good idea.
>
> Steffen
>
>
> Am 07.07.2016 um 18:54 schrieb Cammer, Michael:
>
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>>
>> We are considering a multiphoton purchase and a big issue is
>> illumination.  Putting budget constraints aside and thinking purely of
>> imaging non-destructively in live tissues, what would give us the most
>> flexibility for exciting multiple probes for maximum signal while minimally
>> damaging the biology?
>>
>>
>>
>> We are used to using lasers that tune from approx 700 to 1060 nm and
>> mostly use 890 to 930 nm, but this does not provide good red imaging.  If
>> money were no issue, would we be wise to get a laser such as the dual line
>> Insight or two lasers from 690 to 1080 nm?
>>
>>
>>
>> Some of the questions that have come up are:
>>
>> *         We think a laser that tunesup to 1300 nm would solve the red
>> imaging problem, but for bluer probes (CFP, GFP, etc) & second harmonics of
>> collagen would we need to use a different wavelength?  If so, how long does
>> this take and do the commercial systems support this?
>>
>> *         With a dual line laser that tunes out to 1300 nm is the fixed
>> 1046 nm line really useful?
>>
>> *         Does a dual line system cook the sample?
>>
>>
>>
>> Any thoughts on this (and on specific multiphoton scopes) greatly
>> appreciated.
>>
>>
>>
>> Thank you!
>>
>>
>> =========================================================================
>> Michael Cammer, Microscopy Core & Skirball Institute, NYU Langone Medical
>> Center
>> Cell:  914-309-3270     Office: Skirball 2nd Floor main office
>> http://ocs.med.nyu.edu/microscopy & http://microscopynotes.com/
>>
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>
> --
> ------------------------------------------------------------
> Steffen Dietzel, PD Dr. rer. nat
> Ludwig-Maximilians-Universität München
> Biomedical Center (BMC)
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