I am need to buy a new UV transilluminator. A company presented a new LED - UV transilluminator to me and I am interested in buying it, but don't have any experience with this instrument. Can you give me some advice about this machine?
I have not worked with GEL electrophoresis but I have some experience with various types of LED illuminators. The main difference between the LED sources and previous models that use fluorescent lamps of various types is that the LED sources provide a narrow band of UV centered about 302nm or 365nm. The fluorescent light sources provide a broader excitation which depending on the filters used could excite over the entire UV range. I noted in the web that the manufacturers sell illuminators at either wavelegth or at both - BE CAREFUL make sure the wavelength needed for your application is included. Some manufacturers indicate which wavelength is best for particular assays. Hope this helps.
There are three main differences between the fluorescent bulbs and LEDs, including ultraviolet LEDs.
First. The bulb produces light in the range from 100 nm to the far infrared. You must then select the desired frequency through the filter area, and the quality of the filter effect on the measurement accuracy.
In contrast, the LED light of is localized in a narrow range. It may be dangerous, since invisible ultraviolet radiation can damage the eyes and skin.
It is common practice when the LED is switched off at the opening of the optical channel. However, you should ensure that the relevant electronic protective circuit is installed in your meter
Further, it is important to observe the equality of operational wavelengths of your application and the LED. The further separated these wavelengths, the less noticeable the desired effect.
Second. Fluorescent bulb requires high voltage of about 1 kV and more for operation while the operating voltage of the LED is a few volts.
Third. Usually fluorescent bulb light intensity is constant. Any adjustments are difficult to obtain. Unlike them the LED's light intensity can be easily adjusted in the range 0-100 percent. This property may be very useful in some applications.
I agreed with Alexey. There is one thing that you should keep in mind that although LEDs are narrow sources (in wavelength) there is a tale in the spectrum which expands to the IR region also. Regarding eye safety, the wavelengths below 380 nm typically safe as they are not reaching the retina and below 290 nm they are totally eye safe. Also, since you are using LEDs they are not directed as lasers so the the radiation reaching to eye reduces a lot with the distance. Keep in mind that still some photo-chemical injuries could occur due to UV radiation.
N.B. Usually, there is a wavelength drift in the emission spectrum due to the temperature.
Thank to all of your advie. Because the saler said that LEDs UV is not effect to eye so I am very afraid of the wave length, in this case is detecting DNA with Sybr Green Dye.
Arcording to your answer, I can see that LED UV is more useful than common. Therefore, I will buy a new one.
Thank again and best regards.
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