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Classification of confocal microscopes

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jlribas

Classification of confocal microscopes

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Dear all,
It's just a theoretical question. Can multiphoton microscopes be
classified as confocal microscopes?
Is there any reference published about this type of microscope
classification?

Thank you very much in advance

--
Juan Luis Ribas
Servicio de Microscopía
Centro de Investigación, Tecnología e Innovación
Universidad de Sevilla
Av. Reina Mercedes 4b
41012 Sevilla

Tfno: 954559983

Michael Weber-4

Re: Classification of confocal microscopes

Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

Juan,

a multiphoton system is not confocal. For which purpose do you need the
classification?

Michael

Juan Luis Ribas wrote:

> Search the CONFOCAL archive at
> http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
> Dear all,
> It's just a theoretical question. Can multiphoton microscopes be
> classified as confocal microscopes?
> Is there any reference published about this type of microscope
> classification?
>
> Thank you very much in advance

Beat Ludin

Re: Classification of confocal microscopes

In reply to this post by jlribas

Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

That's a question of definition. IMHO, a MP
microscope can usually be used both in confocal
(when imaging with descanned detectors behind a
pinhole) or non-confocal modes (when imaging with descanned detectors).

Beat

At 10:27 23-07-2008, you wrote:

>Search the CONFOCAL archive at
>http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
>Dear all,
>It's just a theoretical question. Can
>multiphoton microscopes be classified as confocal microscopes?
>Is there any reference published about this type of microscope classification?
>
>Thank you very much in advance
>
>--
>Juan Luis Ribas
>Servicio de Microscopía
>Centro de Investigación, Tecnología e Innovación
>Universidad de Sevilla
>Av. Reina Mercedes 4b
>41012 Sevilla
>
>Tfno: 954559983

George McNamara

Re: Classification of confocal microscopes

In reply to this post by jlribas

Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

Hi Juan,

confocal refers to conjugate pinhole. So on a
MP-only microscope with non-descanned detector(s): no.

However, most MP systems are mounted on a
confocal microscope and the confocal detectors
are often used instead of the NDD's. The confocal
detector pinhole(s) are usually adjustable
(typically to 1 Airy unit, based on the objective
lens NA), but even a "wide open" pinhole may be
much much smaller than if there was no pinhole
aperture diaphragm in place (an NDD condition!).
So, most MP microscopes are multiphoton+confocal.
When writing the methods section, be sure to
specify what light path is used and whether using
NDD or confocal detector, and if the latter, the
number of Airy units for the pinhole size (there
are no laws forcing you to use 1 Airy unit, in
fact 2 Airy units will typically double the amount of light collected).

George
p.s. on an MP system, the confocal detectors
reject stray light, so if the room is not dark
(an MP scope needs to have a black shroud!) the
confocal detectors will usually have a lower
background than the NDD's. A simple test is to
shine a flashlight at the specimen while scanning with either.

At 04:27 AM 7/23/2008, you wrote:

Guy Cox

Re: Classification of confocal microscopes

In reply to this post by jlribas

Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

However, taking into account all these factors, an MP microscope
is 'perfectly' confocal, whereas no 'real' confocal microscope
can ever be. (Unless you have some way of making an infinitely
small pinhole.) See:

Guy Cox & Colin Sheppard, 2004. Practical limits of resolution in
confocal and non-linear microscopy. Microscopy Research & Technique,
63, 18-22

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 George McNamara
Sent: Monday, 28 July 2008 9:30 AM
To: [hidden email]
Subject: Re: Classification of confocal microscopes

Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

Hi Juan,

confocal refers to conjugate pinhole. So on a MP-only microscope with non-descanned detector(s): no.

However, most MP systems are mounted on a confocal microscope and the confocal detectors are often used instead of the NDD's. The confocal detector pinhole(s) are usually adjustable (typically to 1 Airy unit, based on the objective lens NA), but even a "wide open" pinhole may be much much smaller than if there was no pinhole aperture diaphragm in place (an NDD condition!).
So, most MP microscopes are multiphoton+confocal.
When writing the methods section, be sure to specify what light path is used and whether using NDD or confocal detector, and if the latter, the number of Airy units for the pinhole size (there are no laws forcing you to use 1 Airy unit, in fact 2 Airy units will typically double the amount of light collected).

George
p.s. on an MP system, the confocal detectors reject stray light, so if the room is not dark (an MP scope needs to have a black shroud!) the confocal detectors will usually have a lower background than the NDD's. A simple test is to shine a flashlight at the specimen while scanning with either.

At 04:27 AM 7/23/2008, you wrote:

>Search the CONFOCAL archive at
>http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
>Dear all,
>It's just a theoretical question. Can
>multiphoton microscopes be classified as confocal microscopes?
>Is there any reference published about this type of microscope classification?
>
>Thank you very much in advance
>
>--
>Juan Luis Ribas
>Servicio de Microscopía
>Centro de Investigación, Tecnología e Innovación Universidad de Sevilla
>Av. Reina Mercedes 4b
>41012 Sevilla
>
>Tfno: 954559983

George McNamara, Ph.D.
University of Miami, Miller School of Medicine Image Core Miami, FL 33010 [hidden email] [hidden email]
305-243-8436 office
http://home.earthlink.net/~pubspectra/
http://home.earthlink.net/~geomcnamara/
http://www.sylvester.org/research/SR_lab_analytical.asp?ana=desc
(Analytical Imaging Core Facility)

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Beat Ludin

Re: Classification of confocal microscopes

In reply to this post by jlribas

Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

Oops, that should have been "...or non-confocal
modes (when imaging with NON-descanned
detectors).", of course. Sorry for the confusion

Beat

At 10:27 23-07-2008, you wrote: