Intensity of LED excitation (SOLA)

[Steffen Dietzel]

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Dear Listers,

we are about to fix the details on the equipment for several microscopes
for a new core facility. One thing that came up was the excitation light
source for conventional fluorescence for confocals.

I would very much like to switch to LEDs, therefore we consider Lumencor
"SOLA-SM II - White LED source". An article refered to earlier on this
list (doi: 10.7171/jbt.14-2502-001
<http://dx.doi.org/10.7171%2Fjbt.14-2502-001>) described that light
intensitiy of a SOLA is higher over the whole relevant than a "120 W
metal Halide" lamp (Fig 1,
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3970759/figure/F1/), so this
seemed to be a good choice.

I know however heard from two sources that I consider reliable that the
SOLA has significantly less output in the excitation range of orange and
near red dyes (maybe 540 to 600) than a EL6000 using a HXP R 120W metal
halogenid lamp.

Therefore I would appreciate if you could share your thoughts on and
experience with the SOLA, in particular with orange and near red dyes.

Thanks

Steffen


--
------------------------------------------------------------
Steffen Dietzel, PD Dr. rer. nat
Ludwig-Maximilians-Universität München
Walter-Brendel-Zentrum für experimentelle Medizin (WBex)
Head of light microscopy

Marchioninistr. 27
D-81377 München
Germany

[Jens]

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Hi Steffen,

you might find this comparison on Austin Blanco’s blog interesting: http://www.austinblanco.com/blog/light-source-shootout-intensilight-photofluor-spectra-heliophor-and-sola/
From that, the Sola seems to be comparable to the Nikon Intensilight.

If you however go to channel-specific LED sources (fast triggering without mechanical filter switching), I can say from my personal experience in building such systems that indeed, the 560-590ish LEDs are much dimmer than a conventional source in that range. However, one single 470 nm LED (e.g. Luxeon Rebel or Cree Xte) can outperform  the conventional easily in the blue range. If you look at the typical spectrum of a conventional source like the x-cite 120 (http://www.aic-imagecentral.com/products/pdfs/LDGIXCite120QBrochure.pdf) you can see that it has a dip in the blue range but a peak in the “lime” range.
Hopefully LED technology advances soon such that the gap in the lime range is closed.

Best,

Jens

> On Jun 11, 2015, at 12:49 PM, Steffen Dietzel <[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.
> *****
>
> Dear Listers,
>
> we are about to fix the details on the equipment for several microscopes for a new core facility. One thing that came up was the excitation light source for conventional fluorescence for confocals.
>
> I would very much like to switch to LEDs, therefore we consider Lumencor "SOLA-SM II - White LED source". An article refered to earlier on this list (doi: 10.7171/jbt.14-2502-001 <http://dx.doi.org/10.7171%2Fjbt.14-2502-001>) described that light intensitiy of a SOLA is higher over the whole relevant than a "120 W metal Halide" lamp (Fig 1, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3970759/figure/F1/), so this seemed to be a good choice.
>
> I know however heard from two sources that I consider reliable that the SOLA has significantly less output in the excitation range of orange and near red dyes (maybe 540 to 600) than a EL6000 using a HXP R 120W metal halogenid lamp.
>
> Therefore I would appreciate if you could share your thoughts on and experience with the SOLA, in particular with orange and near red dyes.
>
> Thanks
>
> Steffen
>
>
> --
> ------------------------------------------------------------
> Steffen Dietzel, PD Dr. rer. nat
> Ludwig-Maximilians-Universität München
> Walter-Brendel-Zentrum für experimentelle Medizin (WBex)
> Head of light microscopy
>
> Marchioninistr. 27
> D-81377 München
> Germany

[Craig Brideau]

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The yellow-green LEDs, as Jens says, tend to be dimmer. Many of them are
actually phosphor or other down-conversion-process based rather than a
direct LED source. It turns out this is a bit of a tough wavelength to get
direct LEDs for. Part of the problem is sources that use down-conversion
methods tend to be much broader-band than direct LEDs, so not only do you
lose some power from the conversion process, but if you band-filter the
resulting broad spectrum you are throwing away even more light.

Craig

On Thu, Jun 11, 2015 at 11:20 AM, Jens-Bernhard Bosse <[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 Steffen,
>
> you might find this comparison on Austin Blanco’s blog interesting:
> http://www.austinblanco.com/blog/light-source-shootout-intensilight-photofluor-spectra-heliophor-and-sola/
> From that, the Sola seems to be comparable to the Nikon Intensilight.
>
> If you however go to channel-specific LED sources (fast triggering without
> mechanical filter switching), I can say from my personal experience in
> building such systems that indeed, the 560-590ish LEDs are much dimmer than
> a conventional source in that range. However, one single 470 nm LED (e.g.
> Luxeon Rebel or Cree Xte) can outperform  the conventional easily in the
> blue range. If you look at the typical spectrum of a conventional source
> like the x-cite 120 (
> http://www.aic-imagecentral.com/products/pdfs/LDGIXCite120QBrochure.pdf)
> you can see that it has a dip in the blue range but a peak in the “lime”
> range.
> Hopefully LED technology advances soon such that the gap in the lime range
> is closed.
>
> Best,
>
> Jens
>
>
>
> > On Jun 11, 2015, at 12:49 PM, Steffen Dietzel <[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.
> > *****
> >
> > Dear Listers,
> >
> > we are about to fix the details on the equipment for several microscopes
> for a new core facility. One thing that came up was the excitation light
> source for conventional fluorescence for confocals.
> >
> > I would very much like to switch to LEDs, therefore we consider Lumencor
> "SOLA-SM II - White LED source". An article refered to earlier on this list
> (doi: 10.7171/jbt.14-2502-001 <http://dx.doi.org/10.7171%2Fjbt.14-2502-001>)
> described that light intensitiy of a SOLA is higher over the whole relevant
> than a "120 W metal Halide" lamp (Fig 1,
> http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3970759/figure/F1/), so this
> seemed to be a good choice.
> >
> > I know however heard from two sources that I consider reliable that the
> SOLA has significantly less output in the excitation range of orange and
> near red dyes (maybe 540 to 600) than a EL6000 using a HXP R 120W metal
> halogenid lamp.
> >
> > Therefore I would appreciate if you could share your thoughts on and
> experience with the SOLA, in particular with orange and near red dyes.
> >
> > Thanks
> >
> > Steffen
> >
> >
> > --
> > ------------------------------------------------------------
> > Steffen Dietzel, PD Dr. rer. nat
> > Ludwig-Maximilians-Universität München
> > Walter-Brendel-Zentrum für experimentelle Medizin (WBex)
> > Head of light microscopy
> >
> > Marchioninistr. 27
> > D-81377 München
> > Germany
>

[simon walker (BI)-2]

Hi Steffen,
I've been gradually migrating our systems to LED illuminators and have purchased several options including CoolLED pE-300, Lumencor SOLA and Lumencor Spectra-X.  We now have four pE-300 units which in my opinion are ideal as a replacement for a standard mercury burner/metal halide light source on a confocal.  We've used these on our Zeiss 780 and Olympus FV1000 confocals and users can distinguish no significant difference compared with the old illuminators (HXP 120 and mercury burners) in all channels.  The SOLAs are in use on wide-field imaging systems where the pE-300 is no good as it doesn't have the ~630 nm LED for far red fluorophores.  The only significant difference we've found here is that the DAPI excitation (~380 nm) is around 6x weaker (although as the DAPI is typically very bright this doesn't matter), and the 'Texas Red' excitation (~585 nm) is around half as bright compared with the mercury burner.  All other channels are equivalent or brighter, including the 'TRITC' channel (~560 nm).  The Spectra-X is a little different as although the light engine is similar (if not identical) to the SOLA, the electronics permit triggering and intensity control of individual LEDs. This works brilliantly with Nikon Elements software.
I think it's been a while coming, but in my view for most applications LED illuminators are now by far the better option.  Everyone should be switching now!
Simon
P.S. No commercial interest
----------------
Simon A Walker PhD
Imaging Facility Manager
Babraham Institute
Cambridge, UK
CB22 3AT
http://www.babraham.ac.uk/science-services/imaging


-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Steffen Dietzel
Sent: 11 June 2015 17:50
To: [hidden email]
Subject: Intensity of LED excitation (SOLA)

*****
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.
*****

Dear Listers,

we are about to fix the details on the equipment for several microscopes for a new core facility. One thing that came up was the excitation light source for conventional fluorescence for confocals.

I would very much like to switch to LEDs, therefore we consider Lumencor "SOLA-SM II - White LED source". An article refered to earlier on this list (doi: 10.7171/jbt.14-2502-001
<http://dx.doi.org/10.7171%2Fjbt.14-2502-001>) described that light intensitiy of a SOLA is higher over the whole relevant than a "120 W metal Halide" lamp (Fig 1, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3970759/figure/F1/), so this seemed to be a good choice.

I know however heard from two sources that I consider reliable that the SOLA has significantly less output in the excitation range of orange and near red dyes (maybe 540 to 600) than a EL6000 using a HXP R 120W metal halogenid lamp.

Therefore I would appreciate if you could share your thoughts on and experience with the SOLA, in particular with orange and near red dyes.

Thanks

Steffen


--
------------------------------------------------------------
Steffen Dietzel, PD Dr. rer. nat
Ludwig-Maximilians-Universität München
Walter-Brendel-Zentrum für experimentelle Medizin (WBex) Head of light microscopy

Marchioninistr. 27
D-81377 München
Germany
The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT Registered Charity No. 1053902.
The information transmitted in this email is directed only to the addressee. If you received this in error, please contact the sender and delete this email from your system. The contents of this e-mail are the views of the sender and do not necessarily represent the views of the Babraham Institute. Full conditions at: www.babraham.ac.uk<http://www.babraham.ac.uk/terms>

[WHEELER Ann]

Hi Simon /  Steffan

Many thanks for this, it's very helpful. We’ve been carrying out a very similar exercise ourselves. With the CoolLed PE300 white I had I needed to swap out the excitation filter in my TRITC / RFP cube so it worked a bit better with the illumination from the Phosphor. This mitigated somewhat the effect of decreased signal for green excitation fluors.

In a side by side comparison (actually carried out by Matt Pearson and not me) we found the intensity of the LED depended rather on the filterset one was coupling the system up with. Both CoolLED and Lumencor were very happy to advise us of necessary changes in filters to make the best of what we had.

I agree that everyone should be switching, from a facility management point of view it makes life so much easier and cheaper long term and it's considerably better for live experiments and the environment.

Ann


--
The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.


-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Simon Walker
Sent: 12 June 2015 14:01
To: [hidden email]
Subject: Re: Intensity of LED excitation (SOLA)

Hi Steffen,
I've been gradually migrating our systems to LED illuminators and have purchased several options including CoolLED pE-300, Lumencor SOLA and Lumencor Spectra-X.  We now have four pE-300 units which in my opinion are ideal as a replacement for a standard mercury burner/metal halide light source on a confocal.  We've used these on our Zeiss 780 and Olympus FV1000 confocals and users can distinguish no significant difference compared with the old illuminators (HXP 120 and mercury burners) in all channels.  The SOLAs are in use on wide-field imaging systems where the pE-300 is no good as it doesn't have the ~630 nm LED for far red fluorophores.  The only significant difference we've found here is that the DAPI excitation (~380 nm) is around 6x weaker (although as the DAPI is typically very bright this doesn't matter), and the 'Texas Red' excitation (~585 nm) is around half as bright compared with the mercury burner.  All other channels are equivalent or brighter, including the 'TRITC' channel (~560 nm).  The Spectra-X is a little different as although the light engine is similar (if not identical) to the SOLA, the electronics permit triggering and intensity control of individual LEDs. This works brilliantly with Nikon Elements software.
I think it's been a while coming, but in my view for most applications LED illuminators are now by far the better option.  Everyone should be switching now!
Simon
P.S. No commercial interest
----------------
Simon A Walker PhD
Imaging Facility Manager
Babraham Institute
Cambridge, UK
CB22 3AT
http://www.babraham.ac.uk/science-services/imaging


-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Steffen Dietzel
Sent: 11 June 2015 17:50
To: [hidden email]
Subject: Intensity of LED excitation (SOLA)

*****
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.
*****

Dear Listers,

we are about to fix the details on the equipment for several microscopes for a new core facility. One thing that came up was the excitation light source for conventional fluorescence for confocals.

I would very much like to switch to LEDs, therefore we consider Lumencor "SOLA-SM II - White LED source". An article refered to earlier on this list (doi: 10.7171/jbt.14-2502-001
<http://dx.doi.org/10.7171%2Fjbt.14-2502-001>) described that light intensitiy of a SOLA is higher over the whole relevant than a "120 W metal Halide" lamp (Fig 1, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3970759/figure/F1/), so this seemed to be a good choice.

I know however heard from two sources that I consider reliable that the SOLA has significantly less output in the excitation range of orange and near red dyes (maybe 540 to 600) than a EL6000 using a HXP R 120W metal halogenid lamp.

Therefore I would appreciate if you could share your thoughts on and experience with the SOLA, in particular with orange and near red dyes.

Thanks

Steffen


--
------------------------------------------------------------
Steffen Dietzel, PD Dr. rer. nat
Ludwig-Maximilians-Universität München
Walter-Brendel-Zentrum für experimentelle Medizin (WBex) Head of light microscopy

Marchioninistr. 27
D-81377 München
Germany
The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT Registered Charity No. 1053902.
The information transmitted in this email is directed only to the addressee. If you received this in error, please contact the sender and delete this email from your system. The contents of this e-mail are the views of the sender and do not necessarily represent the views of the Babraham Institute. Full conditions at: www.babraham.ac.uk<http://www.babraham.ac.uk/terms>

[Claire Brown]

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We have tested many of the systems on the market including the SOLA, Colibri
and LED120. We work a lot with live cells and in my opinion these sources
are all way brighter than they need to be. We could not image our live cells
without attenuation because they do not move! We use ND filters to work with
0.1% of the blue excitation for EGFP for example.

So in my experience they are plenty bright.

We find longer exposures with lower power (even for fixed cells) gets much
more light out of the fluorophores because of the reduced bleaching.