exposing tritium gels

[Jeffrey Pepe]

On 24 Jul 1995, Bart Sefton wrote:

> In article <Pine.SUN.3.91.950721083342.22235A-100000 at verdi>,
> hroychow at NMSU.EDU (Hiranya Roychowdhury) wrote:
> 
> > With fluors, the secondary emissions do a lot to 'enhance' the signals. 
> > However, I am not sure if a an intensifying screen helps, since I don't 
> > see how the emissions could penetrate the film with strong enough 
> > velocity (if any) to excite the emulsion on the intensifier. I have 
> > traditionally left out screens while exposing materials labeled with 
> > 35S, 14C and 3H. Was I wrong in assuming that the screens would be redundant.
> 
> You were right in assuming that screens don't help.  They augment only 32P
> and 125I.  They are too insensitive to enhance weak betas such as those
> emitted by 3H, 14C, or 35S.
> 
> Bart
 
Actually, screens DO help, at least with tritium.  I also believed they 
would not help, but some reason I tried it one day and the difference was 
dramatic.  Of course, this was using a fluor.  In fact, tritium (again 
enhanced by a fluor) can pass through saran to expose film, although the 
signal is weaker.

Jeff