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George Ring wrote:
SUPPOSEDLY the human eye can see up to 700nm, and women can see longer wavelengths than men. That said, I agree with the others who responded - I haven't met anyone who can see it. A camera, however, or confocal can detect far red.
I think that the human eye has been shown to be capable of detecting photons out beyond 1000 nm--it's just the probability of detection gets pretty low.
--Based on my own lab's experience, I agree with Peter's comment--I haven't met many people who can't see Cy5, for instance. However, intensity is all-important. Filled cells that've been stained with Cy5-streptavidin are easy to see with a 20x 0.7 NA lens by eye and occasionally visible even at 4x. However, smaller structures with weaker labeling (e.g. terminals) are much harder to see and even with brightly labeled cells, the details can get lost.
Re: IR filters on CCD cameras--they indeed can be deadly when trying to image far-red fluorophores!
Martin
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Martin Wessendorf, Ph.D. office: (612) 626-0145
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