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couple of questions about FRAP experiments

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Martin Wessendorf-2

Re: Demonstration of fluorescence for high school

I expect that this wouldn't fly past a safety committee but...when
demonstrating fluorescence, I often will shine a near-UV light at my own
teeth. Teeth fluoresce but very minor amounts of yellowing on them will
attenuate the fluorescence markedly. The appearance is a function of
your last trip to the dentist, but can be suitable for Halloween.

Good luck!

Martin

John Oreopoulos wrote:

> This is not really a microscopy related question, but I figure there
> should be people here who would be able to answer this query. I have a
> friend from another lab who came to me last Friday and asked me if there
> was a simple experiment/demonstration that could be set up to
> demonstrate the concept of fluorescence to high school students. I
> couldn't think of one off the top of my head. The only thing that came
> to mind was the bit about using Fluorescein dye to make the Chicago
> river look green on St. Patrick's day, but I don't know if there's a
> cheap source of Floourscein out there or if it's safe to use with
> younger students. The only other thing I could recall was some basic
> experiment that involved pulling dyes from a commercial highlighter pen
> and showing that they are fluorescent somehow, but I can't remember much
> more than that. Basically, he needs to show that with some substance you
> can put light of one color in and get a different color back out. Didn't
> George Stokes originally discover fluorescence that way somehow?
> Lastly, one beautiful demonstration that I can remember was given by
> Professor David Jameson a couple of years ago at the Biophysical Society
> meeting where in his talk that detailed the history of fluorescence he
> reproduced a phenomenon that was observed long ago in ancient Mexico
> where the wood ("kidney wood") of a specific Mexican tree when dissolved
> in water created an amazing blue glow under UV light. I don't think it
> would be easy to get this wood in Canada, however.
> If anyone knows of a simple (and cheap) way to demonstrate fluorescence,
> please do let me know.
>
>
> John Oreopoulos, BSc,
>
> PhD Candidate
>
> University of Toronto
>
> Institute For Biomaterials and Biomedical Engineering
>
> Centre For Studies in Molecular Imaging
>
>
> Tel: W:416-946-5022
>
>
>

--
Martin Wessendorf, Ph.D. office: (612) 626-0145
Assoc Prof, Dept Neuroscience lab: (612) 624-2991
University of Minnesota Preferred FAX: (612) 624-8118
6-145 Jackson Hall, 321 Church St. SE Dept Fax: (612) 626-5009
Minneapolis, MN 55455 e-mail: [hidden email]

Asson-Batres, Mary Ann

Re: Demonstration of fluorescence for high school

Do you wear safety glasses when you do this? Or does this negate the necessity of UV safety glasses to protect eyes from exposure to UV light? Possibly something that should at least be discussed in a high school class (even if the light source is pointed away from the face).

Mary Ann Asson-Batres, PhD

Professor

Department of Biological Sciences

Tennessee State University

Nashville, TN 37209

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Martin Wessendorf
Sent: Tuesday, November 10, 2009 8:26 AM
To: [hidden email]
Subject: Re: Demonstration of fluorescence for high school

I expect that this wouldn't fly past a safety committee but...when

demonstrating fluorescence, I often will shine a near-UV light at my own

teeth. Teeth fluoresce but very minor amounts of yellowing on them will

attenuate the fluorescence markedly. The appearance is a function of

your last trip to the dentist, but can be suitable for Halloween.

Good luck!

Martin

John Oreopoulos wrote:

> This is not really a microscopy related question, but I figure there

> should be people here who would be able to answer this query. I have a

> friend from another lab who came to me last Friday and asked me if there

> was a simple experiment/demonstration that could be set up to

> demonstrate the concept of fluorescence to high school students. I

> couldn't think of one off the top of my head. The only thing that came

> to mind was the bit about using Fluorescein dye to make the Chicago

> river look green on St. Patrick's day, but I don't know if there's a

> cheap source of Floourscein out there or if it's safe to use with

> younger students. The only other thing I could recall was some basic

> experiment that involved pulling dyes from a commercial highlighter pen

> and showing that they are fluorescent somehow, but I can't remember much

> more than that. Basically, he needs to show that with some substance you

> can put light of one color in and get a different color back out. Didn't

> George Stokes originally discover fluorescence that way somehow?

> Lastly, one beautiful demonstration that I can remember was given by

> Professor David Jameson a couple of years ago at the Biophysical Society

> meeting where in his talk that detailed the history of fluorescence he

> reproduced a phenomenon that was observed long ago in ancient Mexico

> where the wood ("kidney wood") of a specific Mexican tree when dissolved

> in water created an amazing blue glow under UV light. I don't think it

> would be easy to get this wood in Canada, however.

> If anyone knows of a simple (and cheap) way to demonstrate fluorescence,

> please do let me know.

> John Oreopoulos, BSc,

> PhD Candidate

> University of Toronto

> Institute For Biomaterials and Biomedical Engineering

> Centre For Studies in Molecular Imaging

> Tel: W:416-946-5022

Martin Wessendorf, Ph.D. office: (612) 626-0145

Assoc Prof, Dept Neuroscience lab: (612) 624-2991

University of Minnesota Preferred FAX: (612) 624-8118

6-145 Jackson Hall, 321 Church St. SE Dept Fax: (612) 626-5009

Minneapolis, MN 55455 e-mail: [hidden email]

Martin Wessendorf-2

Re: Demonstration of fluorescence for high school

I close my eyes but no, no safety glasses. I'm probably a bad example
for safety but maybe a better one for fun.

Martin

Asson-Batres, Mary wrote:
> Do you wear safety glasses when you do this? Or does this negate the
> necessity of UV safety glasses to protect eyes from exposure to UV
> light? Possibly something that should at least be discussed in a high
> school class (even if the light source is pointed away from the face).

--
Martin Wessendorf, Ph.D. office: (612) 626-0145
Assoc Prof, Dept Neuroscience lab: (612) 624-2991
University of Minnesota Preferred FAX: (612) 624-8118
6-145 Jackson Hall, 321 Church St. SE Dept Fax: (612) 626-5009
Minneapolis, MN 55455 e-mail: [hidden email]

Ignatius, Mike-2

Re: Demonstration of fluorescence for high school

In reply to this post by Asson-Batres, Mary Ann

Auto Parts stores sell a UV leak Detector kit, that comes with ¼ to 1 oz of very concentrated fluorescent dye! When I last bought it, price was under $10 US. Comes with UV glasses and light source too. Here is one link: http://efproducts.com/proddetail.php?prod=436

If not that, then Mountain Dew and Tonic Water show fluorescence as well. The last favorite is the original Stokes experiment using a prism. The UV part (invisible to the eye) can excite these drinks and produce light. It was a show stopper in the 1800’s apparently….

Best,

Mike Ignatius

From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Asson-Batres, Mary
Sent: Tuesday, November 10, 2009 7:22 AM
To: [hidden email]
Subject: Re: Demonstration of fluorescence for high school