Re: LED There Be Light ?

From: Ray Hicks (rayH@FCSPress.com)
Date: Thu Apr 26 2001 - 15:41:22 EST


Brilliant!

Ray
> From: "Kudinov, Yuri" <YKudinov@CHW.edu>
> Date: Wed, 25 Apr 2001 12:37:24 -0700
> To: Cytometry Mailing List <cytometry@flowcyt.cyto.purdue.edu>
> Subject: LED There Be Light ?
>
>
> Hello everyone,
>
> I was so inspired by the recent discussion on buying lab supply at the Home
> Depot that I decided to post a couple of my own money saving tips.
>
> A brief preface. I was looking for a good DNA gel documentation system, when
> I had stumbled upon this: http://www.DarkReader.com. As you see from the
> picture
> http://www.clarechemical.com/HOWITWORKS.GIF, Dark Reader is, basically, a
> light box that anyone can find at the nearest photo shop for under $50. The
> difference is in the light diffuser: instead of sheet of acrylic milk glass,
> Dark Reader is covered with a super-sized bandpass filter. I suspect it is
> the cost of the filter that drives the price of the whole unit to "8 easy
> payments of $99.99". The price was beyond my reach, so I began to look for a
> cheaper alternative. Several hours spent on the Web gave me this:
>
> http://people.bu.edu/efs/Light-Emitting-Diodes-dot-org/chap07/chap07.htm
> http://people.bu.edu/efs/Light-Emitting-Diodes-dot-org/chap07/F07-10-R.jpg
> http://people.bu.edu/efs/Light-Emitting-Diodes-dot-org/chap10/F10-01-R.jpg
> http://people.bu.edu/efs/Light-Emitting-Diodes-dot-org/LED-slide-show.PDF
> (15.3M)
> http://www.eurotechnology.com/bluelaser/blueslide4.html
> http://www.eurotechnology.com/bluelaser/blueslide20.html
> http://www.amazon.com/exec/obidos/ISBN=3540665056
> http://www.ledtronics.com/pages/afewgood.htm
> http://ledmuseum.home.att.net/ledblu2.htm
> http://ledmuseum.home.att.net/ledtur.htm
> http://ledmuseum.home.att.net/leduv.htm
>
> The new generation of Light-Emitting Diodes (LED's). Very bright and very
> affordable. Yet another high-tech revolution I've been missing. I am sure
> that, for many people on this list, these new LED's is quite an old story. I
> am making such a noise because I found very few relevant records on PubMed:
> 10939466, 11005931, 9803466 (to retrieve abstract, paste the comma-delimited
> numbers here: http://www.ncbi.nlm.nih.gov/PubMedOld/medline.html ).
>
> I ordered a small 470 nm flashlight from this online retailer:
> http://www.maxmax.com/aFlashlights.htm . After having played with it for two
> days now, I can enthusiastically recommend this toy to anyone!
>
> What can be done with 5-10 Candela's of pure blue light? Firstly, you can
> epi-illuminate your SYBR Green stained DNA gels. Background is very dark and
> DNA bands are seen very clearly. Why spend $200-$400 on UV epi-illuminator?
> Try a 470 nm LED! It safe for the eyes and it is only $20!
>
> Secondly, you can convert your regular Olympus to a poor man's fluorescent
> microscope. For example, you can preview cell suspension before feeding it
> to cytometer. I checked SYBR Green stained nuclei using 10X and 40X lenses
> -- not bad at all! Background is dark and cells glow very brightly. Just
> don't forget that you have to epi-illuminate cells - do not point the beam
> directly to the lens! You may also find it a good idea to dim the room
> lights and put on some Blue LED music :o)
> http://www.amazon.com/exec/obidos/ASIN/B000038A2S
>
> I tried to induce fluorescence of PI-stained nuclei - no luck. For
> propidium, you may want to try a bluish-green diode. A big list of suppliers
> can be found here: http://ledmuseum.home.att.net/buy.htm
>
> Now, a couple of questions to experts. (1) I need to achieve uniform light
> distribution in order to shoot DNA bands on Polaroid film. Any ideas on how
> to diffuse the flashlight beam evenly over the 4x5-inch area? The Home Depot
> style solutions are particularly welcome. (2) Any ideas on what can be used
> as a good longpass filter? How about amber-glass beer bottle? :o)
>
> Cheers!
>
> Yuri Kudinov
> SVMC, Los Angeles
>
>



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