autorad mystery

John Thaden jjthaden at
Thu Aug 17 14:23:44 EST 1995

jjc4 at po.CWRU.Edu (James J. Campanella) wrote:
>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

I think it has to do with the distribution of your
counts on the membrane.  In my experience,
holding a geiger counter to a hyb'd membrane
tells me more about the completeness of my
washes (i.e. about background) than about
the signal in my bands, dots, etc., because
the counter is viewing such a massive area.

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