> Thomas Urbig <Thomas at hastingslab.harvard.edu> writes:
>Harry.Witchel at bristol.ac.uk (Harry) wrote:
> >Hello Phage-Kings!
> >Also I am having trouble getting my allignment marks to be perfect
> >when doing the autoradiographs of my plaque screens. Currently I place the
> >filters on a saran wrapped piece of stiff film, then cover the filters with
> >another piece of saran wrap. The filters have syringe needle holes punched in
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> > Is there a sane way to make radioactive ink? Is there a better or
> >more consistent pen for radioactivity rather than just using an old marker?
> >Is there an easier way of seeing EXACTLY where the needle hole is (right now
> >my ink spots have a 2 mm margin for error)? I prefer spotting the allignment
> >holes on the filters rather than spotting the back board and alligning later
> >using the filter holes directly because it seems to me that one would get less
> >slippage by missing out the step where the autorad is realligned with the
> >backboard and then the needle holes from the filters are drawn onto the
> > Happy cloning!
> > Harry
> >Harry.Witchel at bristol.ac.uk> >
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>> 2)Instead radioaktive ink (which gives usually pretty big spots) you can use phosphorescent ink. You can get those
> inks in crafts supplies. Put one small spot of ink at the position where the holes are (onto the Saran wrap; I use thin sheet protec=
> tors instead of Saran film because its easier and faster to handle), let it air dry (!) and expose it to normal room light, then exp=
> ose to the film. You can also put the film onto your filter (before or after exposure) and poke holes in the film where your holes i=
Schleicher & Schuell has a membrane with phosphorescent wings. This helps to align the filter, and in addition you can write the
filter number on the wing and have it show up in reverse. Currently we have an 82 mm size. For more information, email
techserv at s-and-s.com or call 1-800-245-4024 and hit '2' for Technical Services.