Phosphoimager any experiences?

Jeremy Weinman jjw at
Mon Nov 30 21:05:55 EST 1992

We've been using the MD system for over a year now and it is great.

In article <SPRENGEL.92Nov28142727 at>, sprengel at (Joerg Sprengel) writes:
> Dear Netters,
> is there sombody who has experiences exposing autoradiograms (all kind
> of blots, sequencing gels, ...) with these machines (ie. trapping the
> energy derived from the radiactivity in a phosphor coated plate, and
> measuring the luminiscence) ?
Yes - we use it for virtually all of our detection applications now.  
Sequencing gels, Southerns, northerns, 35S protein detection, 14C metabolite
analysis etc...  It is very sensitive and will save you a lot of time, or
even permit experiments that could not be done before.  In the "new" 
configuration the MD machine is now rapid enough to scan and print while you 
wait.  Best is that you only need one exposure as you can set your image 
parameters to allow you to scale between any settings in the 0.01 to 100,000 
range for your 0-100% on your image.  Also you can export cut immages for 
quantitation or graphing relative counts.

> We got some, few, informations about the FUJI (c) Bio Imaging Analyser
> BAS1000. Do there exist other manufactures?
Yes.  The MD (Molecular Dynamics) machine which I think was the first on the

> What about the sensitivity of this principle in respect to low
> radiadition trapped on your film/filter. It's difficult to give a
> general rule, I know, but how many Imaging plates (they seem to be
> pretty expensiv) does one need, and how often one can use them?
Immaging plates will last forever, if you don't abuse them (don't have them
in a central facility or loan them out to unknown PhD students).  We find it is
5-10 times as fast as a 2-intesifying screen X-ray system for getting enough
signal above background in a 32-P experiment.  And then you don't need to put 
it down again for another few days to get the *perfect* exposure!  We have 2x
large size and 6x small size for a group with about a dozen molecular 
biologists in it. And we don't but film any more.

> Can you use the laserprintout (300dpi 600dpi?) for documentation or
> publishing purposes? Do you still need the films, even some of them?

We imput the image into a graphics program and annotate, then have this sent of
to either make slides or to be printed onto a  very high resolution colour 
2400dpi printer.  The printing industry refers to these as bromides, and you
should be able to get this done at any professional typographical place.
This gives better reults than even we see on the screen.
You can also put the image through various image enhancement programs, or cut 
and paste montages from different exposures with the settings scaled to give
the same range of black.  You should of course, mention the image processing
you've done for publication.  
> What are the requirements to the hardware? I suspect the mentioned 400
> MB disc storage (SPARC, X11 ??) will be exhausted pretty soon. Can yu
> analyse the image on a remote workstation?
We run 2 networked 486 machines, one with the workstation and another
for analysis and backups.  The analysis 486 has a 600meg HD and we also 
have a 1/2 gigabyte tape drive from Tallgrass Technologies for archiving.
The machines are now hooked up to the campus backbone via ethernet, so people
can get easier access to their immages.
> As allways toward the end of the year, I would appreciate to get some
> hints yesterday :-}, but I'm not disappointed to get some in the near
> future, and of course I will summerize the story.
> Thank you very much,
> --
>            //							     
>           Jorg  Sprengel					     
>     Institute of Genetics                sprengel at
>         Dept. Virology                     aeg07 at    
>          Weyertal 121       	               Tel.: x49 221 470 3405       
>        W5000 Cologne 41		               FAX : x49 221 470 5163       
>            Germany                                                   

Hope all of this helps, and feel free to ask more specific questions,
Dr. Jeremy Weinman				Email:	jjw at	
Plant Microbe Interaction Group			Phone:	61 6 2495051
Research School of Biological Sciences		Fax:	61 6 2490754
Australian National University			Snail:	PO Box 475, Canberra, 
							ACT 2601, AUSTRALIA


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