Advice on fluorescence imaging

[Andy Davies]

My understanding so far is that a royal blue light source such as this CREE XT-E LED XTEARY-00-0000-000000Q04 which has a dominant wavelength range from 450-455nm and a 600m radiant flux would be suitable for imaging marine organisms such as corals and anemones.

An emission filter (dichroic fliter) is then used to narrow the wavelength even more by blocking wavelengths above and below a certain value.

Light that is then produced by the target auto fluorescing which then passes through a long pass barrier filter that only allows wavelengths longer than a certain value to pass through. The wavelength of this barrier filter needs to be matched to the emission filter so that it cuts out wavelengths present in the emission light source.

So, for a 450nm source, a barrier filter with a Wratten value of 3 that blocks wavelengths below 440nm would be suitable https://en.wikipedia.org/wiki/Wratten_number.

I have seen on this forum that Wratten number 12 is recommended but this blocks wavelengths below 500nm.

There are other options for the source wavelength depending on what wavelength is produced by the auto fluorescence of the tissues in the subject.

Any comments, corrections and further insight on the above are most welcome!

[Pau]

Member pwnell has posted some images of fluorescence of corals, for example
http://www.photomacrography.net/forum/v ... p?p=118269 ,searching at the forum you will find more

High power royal blue Cree LEDs are powerful sources to excite algae fluorescence, I'm testing them at my microscope. I think that UV will induce more kinds of fluorescence

Omega, one of the main fluorescence filter makers has an Ebay shop to sell surplus filters at reasonable prices, I've bought some ones from them.