pencil lead attracts hot probes?

[Roland Hübner]

In article <7lgcn0$i16$1 at neuro.usc.edu>, william at neuro.usc.edu (William
Sun) wrote:

> Hello all,
> 
> Perhaps someone could enlighten me why when I mark my nylon filters with 
> pencil and hybridize to radioative probes, the pencil marks appear on the 
> autorad?  Something in the pencil lead attracts probes?  It's not a problem,
> actually quite convenient since I could mark the standards that way and have
> them appear on the autorad.
> 
> William

 Hi,

 ever skipped the probe (i.e, just pencil alone)?

 Roland