UV Microscopy

[samkh918]

Hello,

I don't know if this is the right place to ask this, but I was wondering if there is any danger to the eye associated with looking at fluorescent cells under UV microscope frequently and for long periods. Also once in a while I look at where the ray is touching my plate to make sure I am looking at the right spot, even though the UV ray is not directed at the eye, does looking at it with unprotected eye have any potentials hazards?

Thanks for your help.

[MichaelXY]

I would say that any UV rays the hit your cornea can have a negative effect. Risk to your eyes is high doing this.

[mith]

umm, fluorescent doesn't mean it glows in UV I think.

[canalon]

UV in the eyes are not good, but a good filter cube should pevent yoou from seeing any UV. But it is usually considered safer to use a camera and to pilot the microscope from that.

And mith, FYI, many fluorophores are excited with UV' although they may emit in the visible spectrum.

[mith]

what I meant was, do fluorescents usually glow in the UV range?

[canalon]

what I meant was, do fluorescents usually glow in the UV range?

Some do in the near UV, but sure, that is not very useful. Nevertheless, if your using UV excitation and your filter is not very good/100% efficient, some UV may reach you eyes. But with good material it is OK to look at your sample.

[mith]

thanks for clearing that up

[Fauna]

You don’t need to worry about the UV penetrating all the glass, coating and filters between the objective and the eyepiece. But I did want to mention a problem with some older microscopes that use the big mercury-vapor lamps as a UV source. The housing for these lamps have openings to allow for cooling and a lot of UV escapes thru the openings in the housing.

Many materials are fluorescent in visible light as well as UV but it is harder to see with visible light excitation. The light used for excitation is higher energy (shorter wave length) than the emitted or fluorescent light. If the excitation wavelength is to near the emitted wavelength there is not enough contrast to see the fluorescence.