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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