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Cheap and Reliable Fluoroscope
Can someone provide a link (such as on Amazon) to a cheap and reliable Fluoroscope that is known to work (has the correct wavelength) for visualizing the effects of Vitamin A toxicity?
Check out the automotive fluoroscope in this post: https://ggenereux.blog/2018/08/02/the-four-year-update/
Cheap LED UV-Lights like the automotive leak test kit usually give off a peak at 395nm and a lot of visible violet and blue light.
It causes some fluorescence in the skin but that is not retinol.
Better UVA LEDs peak at 365nm, give off mostly 350nm-380nm and very little visible light.
Mercury vapour based blacklight blue bulbs mostly emit from 310nm-420nm, peaking around 350nm-360nm.
Expensive flouroscopes have mercury vapour bulbs and a bandpass filter that only lets very specific wavelength pass.
Retinol has a peak excitation at around 330nm (depends on temperature and solvent) and emits around 460nm (light blue)
Many retinol esters have a fluorescence and autofluorescence (keep glowing if excited enough) at different wavelengths and often emit in a greenish or yellowish tone (butter glows this way under a blacklight).
To make it more confusing:
Collagen peptides and melanin in the skin are excited at certain UV wavelengths (270-410nm) and emit different visible colors. Lipofuscin has a fluorescence, folic acid has, riboflavin does and more...
You are only able to reliably detect retinol in the skin with a fluoroscope fitted with a narrow bandpass filter.
Retinol esters have different excitation/emission wavelengths.
Carotenes and retinoic acid will not be detected by fluorescence.
If you still want a cheap solution to play with buy a rather powerful mercury vapor Black Light Blue bulb or a 365nm LED direct from China.
Spiral CFLs usually give off too much visible light and have a poor performance.