Hi!
Does anyone know where can I find information about the Leica AOBS spectral response? ...or from the AOTFs they use. All the best, -- Nuno Moreno, PhD ___________ Equipment Management Unit, Head Instituto Gulbenkian de Ciência Fundação Calouste Gulbenkian phone +351 214464606 fax +351 214407970 |
Dear Nuno,
The 'Product & Technology Guide' from Leica Confocal Systems contains some information on the AOBS. I found a diagram showing linear transmission of 92% for the full spectral range (450nm - 750nm). Excitation light will be blocked with a spectral width of approx. 1nm. The AOTF should have similar characteristics. Hope that helps. Nice regards, Ralf Ralf Zenke Max Planck Institute of Biochemistry Core Facility Am Klopferspitz 18 DE-82152 Martinsried near Munich GERMANY Phone: (+49) (89) 8578 3798 Fax: (+49) (89) 8578 2847 www.biochem.mpg.de Hi! Does anyone know where can I find information about the Leica AOBS spectral response? ...or from the AOTFs they use. All the best,
|
Boswell, Carl A - (cboswell) |
In reply to this post by Nuno Moreno
I'd wager that there are many of us that would like to see that.
Good luck, c Carl A. Boswell, Ph.D. Molecular and Cellular Biology University of Arizona 520-954-7053 FAX 520-621-3709 ----- Original Message ----- From: "Nuno Moreno" <[hidden email]> To: <[hidden email]> Sent: Wednesday, November 18, 2009 7:27 AM Subject: AOBS spectrum > Hi! > > Does anyone know where can I find information about the Leica AOBS > spectral response? ...or from the AOTFs they use. > > All the best, > -- > Nuno Moreno, PhD > ___________ > Equipment Management Unit, Head > Instituto Gulbenkian de Ciência > Fundação Calouste Gulbenkian > phone +351 214464606 > fax +351 214407970 > |
>I'd wager that there are many of us that would like to see that.
>Good luck, > >c > >Carl A. Boswell, Ph.D. >Molecular and Cellular Biology >University of Arizona >520-954-7053 >FAX 520-621-3709 >----- Original Message ----- From: "Nuno Moreno" <[hidden email]> >To: <[hidden email]> >Sent: Wednesday, November 18, 2009 7:27 AM >Subject: AOBS spectrum Hi all, A measured response of the Leica AOBS can be found as Figure 3-23 on page 57 of "The Handbook". I gather that actually measuring it was very difficult but it came from Leica. Cheers, Jim Pawley ********************************************** Prof. James B. Pawley, Ph. 608-263-3147 Room 223, Zoology Research Building, FAX 608-265-5315 1117 Johnson Ave., Madison, WI, 53706 [hidden email] 3D Microscopy of Living Cells Course, June 12-24, 2010, UBC, Vancouver Canada Info: http://www.3dcourse.ubc.ca/ Applications due by March 15, 2010 "If it ain't diffraction, it must be statistics." Anon. > >>Hi! >> >>Does anyone know where can I find information >>about the Leica AOBS spectral response? ...or >>from the AOTFs they use. >> >>All the best, >>-- >>Nuno Moreno, PhD >>___________ >>Equipment Management Unit, Head >>Instituto Gulbenkian de Ciência >>Fundação Calouste Gulbenkian >>phone +351 214464606 >>fax +351 214407970 -- |
Thank you Pawley,
I know that one but I wonder if there are other sources. I'm just as asking this because if you measure the system performance from 400 to 700 it gives you a flat response. I was expecting it to behave in accordance to a PMT profile. Nuno Moreno, PhD ___________ Equipment Management Unit, Head Instituto Gulbenkian de Ciência Fundação Calouste Gulbenkian phone +351 214464606 fax +351 214407970 James Pawley escreveu: >> I'd wager that there are many of us that would like to see that. >> Good luck, >> >> c >> >> Carl A. Boswell, Ph.D. >> Molecular and Cellular Biology >> University of Arizona >> 520-954-7053 >> FAX 520-621-3709 >> ----- Original Message ----- From: "Nuno Moreno" >> <[hidden email]> >> To: <[hidden email]> >> Sent: Wednesday, November 18, 2009 7:27 AM >> Subject: AOBS spectrum > > > Hi all, > > A measured response of the Leica AOBS can be found as Figure 3-23 on > page 57 of "The Handbook". > > I gather that actually measuring it was very difficult but it came from > Leica. > > Cheers, > > Jim Pawley > > ********************************************** > Prof. James B. Pawley, Ph. > 608-263-3147 Room 223, Zoology Research > Building, FAX 608-265-5315 > 1117 Johnson Ave., Madison, WI, 53706 [hidden email] > 3D Microscopy of Living Cells Course, June 12-24, 2010, UBC, Vancouver > Canada > Info: http://www.3dcourse.ubc.ca/ Applications due by March 15, > 2010 > "If it ain't diffraction, it must be statistics." Anon. > >> >>> Hi! >>> >>> Does anyone know where can I find information about the Leica AOBS >>> spectral response? ...or from the AOTFs they use. >>> >>> All the best, >>> -- >>> Nuno Moreno, PhD >>> ___________ >>> Equipment Management Unit, Head >>> Instituto Gulbenkian de Ciência >>> Fundação Calouste Gulbenkian >>> phone +351 214464606 >>> fax +351 214407970 > > |
I suppose they build in a correction for the detector response - after all, it is supposed to be a spectrometer.
Guy Optical Imaging Techniques in Cell Biology by Guy Cox CRC Press / Taylor & Francis http://www.guycox.com/optical.htm ______________________________________________ Associate Professor Guy Cox, MA, DPhil(Oxon) Electron Microscope Unit, Madsen Building F09, University of Sydney, NSW 2006 ______________________________________________ Phone +61 2 9351 3176 Fax +61 2 9351 7682 Mobile 0413 281 861 ______________________________________________ http://www.guycox.net -----Original Message----- From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Nuno Moreno Sent: Friday, 20 November 2009 3:38 AM To: [hidden email] Subject: Re: AOBS spectrum Thank you Pawley, I know that one but I wonder if there are other sources. I'm just as asking this because if you measure the system performance from 400 to 700 it gives you a flat response. I was expecting it to behave in accordance to a PMT profile. Nuno Moreno, PhD ___________ Equipment Management Unit, Head Instituto Gulbenkian de Ciência Fundação Calouste Gulbenkian phone +351 214464606 fax +351 214407970 James Pawley escreveu: >> I'd wager that there are many of us that would like to see that. >> Good luck, >> >> c >> >> Carl A. Boswell, Ph.D. >> Molecular and Cellular Biology >> University of Arizona >> 520-954-7053 >> FAX 520-621-3709 >> ----- Original Message ----- From: "Nuno Moreno" >> <[hidden email]> >> To: <[hidden email]> >> Sent: Wednesday, November 18, 2009 7:27 AM >> Subject: AOBS spectrum > > > Hi all, > > A measured response of the Leica AOBS can be found as Figure 3-23 on > page 57 of "The Handbook". > > I gather that actually measuring it was very difficult but it came > from Leica. > > Cheers, > > Jim Pawley > > ********************************************** > Prof. James B. Pawley, Ph. > 608-263-3147 Room 223, Zoology Research > Building, FAX 608-265-5315 > 1117 Johnson Ave., Madison, WI, 53706 [hidden email] 3D Microscopy > of Living Cells Course, June 12-24, 2010, UBC, Vancouver Canada > Info: http://www.3dcourse.ubc.ca/ Applications due by March 15, > 2010 > "If it ain't diffraction, it must be statistics." Anon. > >> >>> Hi! >>> >>> Does anyone know where can I find information about the Leica AOBS >>> spectral response? ...or from the AOTFs they use. >>> >>> All the best, >>> -- >>> Nuno Moreno, PhD >>> ___________ >>> Equipment Management Unit, Head >>> Instituto Gulbenkian de Ciência >>> Fundação Calouste Gulbenkian >>> phone +351 214464606 >>> fax +351 214407970 > > No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.707 / Virus Database: 270.14.73/2512 - Release Date: 11/19/09 06:41:00 |
Koo, Lily (NIH/NIAID) [E] |
Hello list,
A while ago (2005 to be precise) there was a list exchange regarding the Forster distance of FRET pairs. Iain Johnson from Molecular Probe (now Invitrogen) posted a link to his measured table of Forster distance for Alexa dyes. Of course the link is no longer valid. I am wondering if Iain could generously provide that information again? Also, does anyone know of other existing tables for the other FRET pairs? Thanks, Lily |
Johnson, Iain-2 |
Apologies for the broken links. The ones below are current:
http://www.invitrogen.com/site/us/en/home/References/Molecular-Probes-The-Handbook/tables/R0-values-for-some-Alexa-Fluor-dyes.html http://www.invitrogen.com/site/us/en/home/References/Molecular-Probes-The-Handbook/tables/Ro-values-for-QSY-and-dabcyl-quenchers.html For FPs there are some good literature sources including: Anal Biochem. 2000 284(2):438-40. Förster distances between green fluorescent protein pairs. Patterson GH, Piston DW, Barisas BG. http://www.ncbi.nlm.nih.gov/sites/entrez/10964438 Iain -----Original Message----- From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Koo, Lily (NIH/NIAID) [E] Sent: Thursday, November 19, 2009 2:41 PM To: [hidden email] Subject: FRET Forster distance - Iain Johnson's table and others Hello list, A while ago (2005 to be precise) there was a list exchange regarding the Forster distance of FRET pairs. Iain Johnson from Molecular Probe (now Invitrogen) posted a link to his measured table of Forster distance for Alexa dyes. Of course the link is no longer valid. I am wondering if Iain could generously provide that information again? Also, does anyone know of other existing tables for the other FRET pairs? Thanks, Lily |
Kimmo K Tanhuanpaa |
In reply to this post by Koo, Lily (NIH/NIAID) [E]
On Thu, 19 Nov 2009, Koo, Lily (NIH/NIAID) [E] wrote:
Hi, > A while ago (2005 to be precise) there was a list exchange regarding the > Forster distance of FRET pairs. Iain Johnson from Molecular Probe (now > Invitrogen) posted a link to his measured table of Forster distance for > Alexa dyes. Of course the link is no longer valid. You can find it in Molecular Probes Handbook, table 1.6: http://www.invitrogen.com/site/us/en/home/References/Molecular-Probes-The-Handbook/tables/R0-values-for-some-Alexa-Fluor-dyes.html.html Cheers, Kimmo _____________________________________________________________________ Mr. Kimmo Tanhuanpää, PhD (Biochemistry) Head of Light Microscopy Unit, Institute of Biotechnology, University of Helsinki http://www.biocenter.helsinki.fi/bi/lmu/ |
In reply to this post by Guy Cox
It is for me hard to understand why are they throwing away efficiency in
the blue/green range. In my head making it work as a spectrometer does not worth it. I hope this is only true if we use the lambda mode! Nuno Moreno, PhD ___________ Equipment Management Unit, Head Instituto Gulbenkian de Ciência Fundação Calouste Gulbenkian phone +351 214464606 fax +351 214407970 Guy Cox escreveu: > I suppose they build in a correction for the detector response - after all, it is supposed to be a spectrometer. > > Guy > > > > Optical Imaging Techniques in Cell Biology > by Guy Cox CRC Press / Taylor & Francis > http://www.guycox.com/optical.htm > ______________________________________________ > Associate Professor Guy Cox, MA, DPhil(Oxon) > Electron Microscope Unit, Madsen Building F09, > University of Sydney, NSW 2006 > ______________________________________________ > Phone +61 2 9351 3176 Fax +61 2 9351 7682 > Mobile 0413 281 861 > ______________________________________________ > http://www.guycox.net > -----Original Message----- > From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Nuno Moreno > Sent: Friday, 20 November 2009 3:38 AM > To: [hidden email] > Subject: Re: AOBS spectrum > > Thank you Pawley, > > I know that one but I wonder if there are other sources. I'm just as asking this because if you measure the system performance from 400 to 700 it gives you a flat response. I was expecting it to behave in accordance to a PMT profile. > > Nuno Moreno, PhD > ___________ > Equipment Management Unit, Head > Instituto Gulbenkian de Ciência > Fundação Calouste Gulbenkian > phone +351 214464606 > fax +351 214407970 > > > James Pawley escreveu: >>> I'd wager that there are many of us that would like to see that. >>> Good luck, >>> >>> c >>> >>> Carl A. Boswell, Ph.D. >>> Molecular and Cellular Biology >>> University of Arizona >>> 520-954-7053 >>> FAX 520-621-3709 >>> ----- Original Message ----- From: "Nuno Moreno" >>> <[hidden email]> >>> To: <[hidden email]> >>> Sent: Wednesday, November 18, 2009 7:27 AM >>> Subject: AOBS spectrum >> >> Hi all, >> >> A measured response of the Leica AOBS can be found as Figure 3-23 on >> page 57 of "The Handbook". >> >> I gather that actually measuring it was very difficult but it came >> from Leica. >> >> Cheers, >> >> Jim Pawley >> >> ********************************************** >> Prof. James B. Pawley, Ph. >> 608-263-3147 Room 223, Zoology Research >> Building, FAX 608-265-5315 >> 1117 Johnson Ave., Madison, WI, 53706 [hidden email] 3D Microscopy >> of Living Cells Course, June 12-24, 2010, UBC, Vancouver Canada >> Info: http://www.3dcourse.ubc.ca/ Applications due by March 15, >> 2010 >> "If it ain't diffraction, it must be statistics." Anon. >> >>>> Hi! >>>> >>>> Does anyone know where can I find information about the Leica AOBS >>>> spectral response? ...or from the AOTFs they use. >>>> >>>> All the best, >>>> -- >>>> Nuno Moreno, PhD >>>> ___________ >>>> Equipment Management Unit, Head >>>> Instituto Gulbenkian de Ciência >>>> Fundação Calouste Gulbenkian >>>> phone +351 214464606 >>>> fax +351 214407970 >> > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 9.0.707 / Virus Database: 270.14.73/2512 - Release Date: 11/19/09 06:41:00 > |
George McNamara |
In reply to this post by Koo, Lily (NIH/NIAID) [E]
Hi Lily,
You can calculate Ro, as well as J* (spectral overlap integral - in many ways more useful than Ro) using the spectra in the PubSpectra xlsx file and the Szollosi&Horvath FRET Excel file, both in http://www.sylvester.org/AICF/pubspectra.zip I don't have the Excel matrices skill set to create a comprehensive FRET donor vs acceptor table, but perhaps you or someone on the listserv would like to do this - whoever does it could write the work up for publication in Biotechniques, Nature Methods, etc. George p.s. there is also a nascent FRET calculator option at http://www.mcb.arizona.edu/ipc/fret/index.html (3rd tab above the graph box) - Carl Boswell at UA might benefit from a financial donation to make the "Calculate FRET" button fully functional (or my choice of Alexa Fluor 488 and 568 might not have QY or another variable). p.p.s. Ro vs J* ... Ro depends on quantum yield and somewhat on refractive index which many papers do not mention. My understanding is that the RI(s) in an ~1 um diameter sphere surrounding the molecules is "sensed' (search Pubmed for Suhling refractive index for an entry point to this literature). RI 1.34 (water) or RI 1.5 (immersion oil? glass? solid protein?) which are clearly not correct for cytosol (which is ~1.38 for mammalian cells). It would be useful to define a normalized J* parameter that results in easy to compare values (much like GM units (10^50 multiplier) puts multiphoton absorption into a easy to read range, or QY * Extinction coefficient / 1000 makes fluorophore efficiencies easier to read. At 05:41 PM 11/19/2009, you wrote: >Hello list, > >A while ago (2005 to be precise) there was a list exchange regarding >the Forster distance of FRET pairs. Iain Johnson from Molecular >Probe (now Invitrogen) posted a link to his measured table of >Forster distance for Alexa dyes. Of course the link is no longer >valid. I am wondering if Iain could generously provide that >information again? Also, does anyone know of other existing tables >for the other FRET pairs? > >Thanks, > >Lily George McNamara, Ph.D. Image Core Manager Analytical Imaging Core Facility University of Miami, Miller School of Medicine Miami, FL 33136 [hidden email] [hidden email] 305-243-8436 office http://www.sylvester.org/AICF (Analytical Imaging Core Facility) http://www.sylvester.org/AICF/pubspectra.zip (the entire 2000+ spectra .xlsx file is in the zip file) http://home.earthlink.net/~geomcnamara |
Mark Cannell |
Hi All,
I must admit to being kind of bemused by this obsession with theoretical FRET distances in cell experiments. In view of all the uncertainties in dipole orientattion (etc.) I think that all you can really say is that if FRET occurs the dipoles are very close together (a few nm). If it changes, they are moving (translation and/or orientation) or the local environment is changing (lipid<-->cytosol, another protein entering/leaving) -and you really don't know which, of any of these, is the cause. I think it very revealing when people talk about absolute FRET distances and their changes when they really don't know what is going on. Why do papers generally not talk about the possible change in conformation/orientation of a protein or even that that insertion/removal of a third protein may be responsible for a FRET change? Cheers Mark George McNamara wrote: > Hi Lily, > > You can calculate Ro, as well as J* (spectral overlap integral - in > many ways more useful than Ro) using the spectra in the PubSpectra > xlsx file and the Szollosi&Horvath FRET Excel file, both in > http://www.sylvester.org/AICF/pubspectra.zip > > I don't have the Excel matrices skill set to create a comprehensive > FRET donor vs acceptor table, but perhaps you or someone on the > listserv would like to do this - whoever does it could write the work > up for publication in Biotechniques, Nature Methods, etc. > > George > p.s. there is also a nascent FRET calculator option at > http://www.mcb.arizona.edu/ipc/fret/index.html (3rd tab above the > graph box) - Carl Boswell at UA might benefit from a financial > donation to make the "Calculate FRET" button fully functional (or my > choice of Alexa Fluor 488 and 568 might not have QY or another variable). > > p.p.s. Ro vs J* ... Ro depends on quantum yield and somewhat on > refractive index which many papers do not mention. My understanding is > that the RI(s) in an ~1 um diameter sphere surrounding the molecules > is "sensed' (search Pubmed for Suhling refractive index for an entry > point to this literature). RI 1.34 (water) or RI 1.5 (immersion oil? > glass? solid protein?) which are clearly not correct for cytosol > (which is ~1.38 for mammalian cells). It would be useful to define a > normalized J* parameter that results in easy to compare values (much > like GM units (10^50 multiplier) puts multiphoton absorption into a > easy to read range, or QY * Extinction coefficient / 1000 makes > fluorophore efficiencies easier to read. > > At 05:41 PM 11/19/2009, you wrote: >> Hello list, >> >> A while ago (2005 to be precise) there was a list exchange regarding >> the Forster distance of FRET pairs. Iain Johnson from Molecular >> Probe (now Invitrogen) posted a link to his measured table of Forster >> distance for Alexa dyes. Of course the link is no longer valid. I >> am wondering if Iain could generously provide that information >> again? Also, does anyone know of other existing tables for the other >> FRET pairs? >> >> Thanks, >> >> Lily > > > > > > > > George McNamara, Ph.D. > Image Core Manager > Analytical Imaging Core Facility > University of Miami, Miller School of Medicine > Miami, FL 33136 > [hidden email] > [hidden email] > 305-243-8436 office > http://www.sylvester.org/AICF (Analytical Imaging Core Facility) > http://www.sylvester.org/AICF/pubspectra.zip (the entire 2000+ spectra > .xlsx file is in the zip file) > http://home.earthlink.net/~geomcnamara |
Vitaly Boyko |
Well, as most of the fluorescent proteins are either dimers or worse upon desired over expression, "for easy going" (sometimes even with the letter "m" in front of). The latter fact would yield in positive but often "wishful" FRET signal, especially when carefully limited number of controls have been designed to be " biophysically smart". Therefore, all the discussions around the Ro or J seem to be redundunt... You might recollect that the famous textbook experiments have been performed with free, soluble donor-acceptor pairs at concentrations far above physiologically acceptable limits.
...my two cents...
Vitaly From: Mark Cannell <[hidden email]> To: [hidden email] Sent: Sun, November 22, 2009 1:51:19 PM Subject: Re: FRET Forster distance - Iain Johnson's table and others Hi All, I must admit to being kind of bemused by this obsession with theoretical FRET distances in cell experiments. In view of all the uncertainties in dipole orientattion (etc.) I think that all you can really say is that if FRET occurs the dipoles are very close together (a few nm). If it changes, they are moving (translation and/or orientation) or the local environment is changing (lipid<-->cytosol, another protein entering/leaving) -and you really don't know which, of any of these, is the cause. I think it very revealing when people talk about absolute FRET distances and their changes when they really don't know what is going on. Why do papers generally not talk about the possible change in conformation/orientation of a protein or even that that insertion/removal of a third protein may be responsible for a FRET change? Cheers Mark George McNamara wrote: > Hi Lily, > > You can calculate Ro, as well as J* (spectral overlap integral - in many ways more useful than Ro) using the spectra in the PubSpectra xlsx file and the Szollosi&Horvath FRET Excel file, both in http://www.sylvester.org/AICF/pubspectra.zip > > I don't have the Excel matrices skill set to create a comprehensive FRET donor vs acceptor table, but perhaps you or someone on the listserv would like to do this - whoever does it could write the work up for publication in Biotechniques, Nature Methods, etc. > > George > p.s. there is also a nascent FRET calculator option at http://www.mcb.arizona.edu/ipc/fret/index.html (3rd tab above the graph box) - Carl Boswell at UA might benefit from a financial donation to make the "Calculate FRET" button fully functional (or my choice of Alexa Fluor 488 and 568 might not have QY or another variable). > > p.p.s. Ro vs J* ... Ro depends on quantum yield and somewhat on refractive index which many papers do not mention. My understanding is that the RI(s) in an ~1 um diameter sphere surrounding the molecules is "sensed' (search Pubmed for Suhling refractive index for an entry point to this literature). RI 1.34 (water) or RI 1.5 (immersion oil? glass? solid protein?) which are clearly not correct for cytosol (which is ~1.38 for mammalian cells). It would be useful to define a normalized J* parameter that results in easy to compare values (much like GM units (10^50 multiplier) puts multiphoton absorption into a easy to read range, or QY * Extinction coefficient / 1000 makes fluorophore efficiencies easier to read. > > At 05:41 PM 11/19/2009, you wrote: >> Hello list, >> >> A while ago (2005 to be precise) there was a list exchange regarding the Forster distance of FRET pairs. Iain Johnson from Molecular Probe (now Invitrogen) posted a link to his measured table of Forster distance for Alexa dyes. Of course the link is no longer valid. I am wondering if Iain could generously provide that information again? Also, does anyone know of other existing tables for the other FRET pairs? >> >> Thanks, >> >> Lily > > > > > > > > George McNamara, Ph.D. > Image Core Manager > Analytical Imaging Core Facility > University of Miami, Miller School of Medicine > Miami, FL 33136 > [hidden email] > [hidden email] > 305-243-8436 office > http://www.sylvester.org/AICF (Analytical Imaging Core Facility) > http://www.sylvester.org/AICF/pubspectra.zip (the entire 2000+ spectra .xlsx file is in the zip file) > http://home.earthlink.net/~geomcnamara |
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