autorad mystery

Tim Dunn t.dunn at
Sun Aug 13 18:48:06 EST 1995

In article <40avp3$80o at usenet.INS.CWRU.Edu>, jjc4 at po.CWRU.Edu (James J.
Campanella) wrote:

> Hi,
> I seem to have run into a weird problem which I am having trouble
> explaining. The last 3 DNA blots that I have exposed to film have
> shown only a faint signal on the film. This is not necessarily 
> strange except that each blot has had a signal of ~1000 cpm; in
> my experience that is more than enough to give at least some
> signal overnight, but I am getting only a barely discernable
> background. The probes are P32-labelled and the blots newly
> hybridized. There seems to be nothing wrong with the developing
> soln because other labs are not having problems. We are using
> FujiRX film, but I have no idea whether that's a contributing factor
> or not. 
> Anyway, to sum it up, this seems to go against the laws of nature.
> If you expose film to a radioactive source, it should darken--
> even if the darkening is just background crud and not a decent
> signal.
> Does anyone out there have the faintest idea what might be going
> on here? I am nearing my wits end. Thanks.
> Jim Campanella
> Case Western University
> Biology Dept.
> -- 
Wouldn't simply be the developing process, exhausted developer etc...?

Tim Dunn
Centre for Molecular and Cellular Biology
University of Queensland
Australia 4075
e-mail t.dunn at
phone  (07) 365 4565
fax    (07) 365 4388 

More information about the Methods mailing list