Hand-held UV wand: the most useful thing ever? - Gel electrophoresis, southerns and northerns (Nov/28/2005 )

I'm not a sales rep for a UV wand dealer or anything, but this hand-held UV wand is the most time-saving piece of equipment we've obtained recently. If you include EtBr in your gels, you see exactly where your DNA has run to without even removing the gel from the tank, which saves hassles every day (our gel-doc system is up one flight of stairs!). I also suspend it above the gel when cutting out bands, so I can do it at my bench and the UV shines downwards rather than upwards, which is less hazardous.

You can use it to check nucleic acid transfer to nylon membranes without staining the membrane. For example, Maniatis says to stain your Northern blot with methylene blue to check that the transfer was successful, but this can slightly reduce hybridisation signal later on (i've heard). Now, I just check with the UV wand, since I have EtBr in my RNA/glyoxal loading buffer, and this seems to remain associated with the RNA during electrophoresis and transfer, and even if I partially hydrolyse the RNA in the gel using 0.05M NaOH prior to transfer. You can mark the position of the MW size-markers using radioactive ink directly on the membrane rather than relying on a scaled photograph of the gel which was taken prior to transfer. This takes out one degree of inaccuracy when estimating the MW of a band.

Although our wand in low-energy (302nm) I'm careful not to expose my RNA lanes on the blot to UV for too long, as excessive cross-linking can reduce hybe signal according to Millipore.

Yes, you should always use eye protection. Although it's not as powerful as the UV you get from the transilluminator or a mercury lamp, the fact that it's hand-held means you should be careful about where it's pointed before you turn it on.

Oh, and speaking of safety, you can also use it to see if any of your messy co-workers have contaminated your bench with ethidium bromide or other things, even if they think they cleaned up their spills enough so you wouldn't know

Hi microphobe,

Where did you get the wand and how is it different from regular hand-held UV light? I couldn't find it through Google.

That wand is also very helpful if you want to check how contaminated you lab is with EtBr. In one of the labs where I've worked as an assistant, students have their practical courses, when they were done, the whole lab was illuminating and it took a week to get it cleaned and disinfected...

Cool stuff.

How much does it cost?

Ours is a UVP (www.uvp.com) model UVM-57. I've seen it for sale at US$200 or US$270 after googling for the model name. But we inherited ours for free. Apparently it hasn't needed a bulb replacement in ~5 years.

One small bug: ours tends to get hot even if the lamp is off, unless we switch off the power at the wall. So it must be drawing current somehow, even though it passed electrical safety testing. I don't know if this is a problem with this model in general or just with our unit - it was probably modified for the Australian 240 volt power outlet. We just switch it off at the wall but if you plan on getting this model, you might want to ask the saleperson about why this happens.

EDIT: PCRman, I think it may be the same thing by a different name

One more great thing about Hand held UV-wands:

We stick them into our co2 incubators to decontaminate.