Another great idea!
Okay now, we do get lots of light up here in Canada contrary to what  
most people think. In fact, it was a balmy 18 degrees C in Toronto  
today and yesterday. Not bad for November. Now back to ice fishing in  
my igloo.

John

On 9-Nov-09, at 11:21 PM, Dale Callaham wrote:

> John,
>
> This has nothing to do with microscopy but it doesn't involve  
> "chemicals" either so it may be easier to deal with in a HS. Get a  
> bottle of Lysol - I'm looking at my bottle of "Lemon Breeze All- 
> Purpose 3-in-1 Dilutable". Either the concentrate or a modest  
> dilution, if held close to a standard "white" fluorescent tube  
> (tube or compact style) will show  nice "fluorescein" green at the  
> top where the light is absorbed, and the green fades a bit below  
> the surface of the solution as the blue-UV has been absorbed. I'm  
> sure the UV flashlights or a blacklight poster (BLB (blacklight- 
> blue) bulb will be more dramatic. A beam of sunlight works too -  
> oh, I forgot - it's Canada!
>
> Cheers!
>
> Dale
>
> 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