Phosphorimagers...opinions on brands?

mts at mts at
Sun May 8 19:09:57 EST 1994

In article <c557652.16.00164916 at> c557652 at (Robert Woodward) writes:
>In article <Pine.3.89.9405021417.A16917-0100000 at> brunstei at UNIXG.UBC.CA (John Brunstein) writes:
>>From: brunstei at UNIXG.UBC.CA (John Brunstein)
>>Subject: Phosphorimagers...opinions on brands?
>>Date: 2 May 1994 14:40:43 -0700
>>Hello all!
>>        We finally have the money for a phosphorimager in our 
>>collectively sweaty hands and although we have seen demos of both the 
>>Molecular Dynamics and Bio-Rad machines we would be interested in hearing 
>>from satisfied or disatisfied users of these or other makes to help in 
>>making our final choice.
>>        Also, what sort of bulk storage media are people using for the 
>>data files? WORM, Magneto-optical,Colorado drive, Bernouli Boxes/SyQuest 
>>        Any info on these would be greatly appreciated.  Thanks! =:^>
>One thing to consider is the difference between a machine that reads the 
>signal directly from the gel (or whatever) and a machine that requires a 
>screen that is exposed to the gel, then scanned by the machine.  A member 
>of our lab recently did some experiments that ended up with a very weak 
>signal.  Thus they required a fairly long exposure to the screen (it was a 
>week or two).  If this much time was spent IN THE MACHINE, or even a fraction 
>of this time, it would be unavailable to others.  With a screen system, 
>several experiments can be exposing at a time, then each scanned with only 
>limited machine time.  This can be especially useful if several labs will use 
>be using it.  
> \/-\/-\/-\/-\/-\/-\/-\/-\/-\/-\/-\/-\/-\/-\/-\/-\/
>> Robert Woodward, c557652 at    <
>| Department of Physiology, University of Missouri |
>> (314) 882-5374, FAX: (314) 884-4276              < 
> /\-/\-/\-/\-/\-/\-/\-/\-/\-/\-/\-/\-/\-/\-/\-/\-/\
We have had an MD PI for about 2yrs now and find it very good.
I agree wit the above statement, unless you machine is VERY sensitive
weak samples can tie up the machine while others wait in line. This can
make for bad lab and inter-lab relations. I think a screen based system
is therefore preferable. The only problem is that the MD screens + cassettes
are about $US1000 each so your initial investment is high. but hey the 
machine is worth a packet on its own.

We have had a slight problem with the screens though. MD firstly told us
to wrap the samples in plastic(saran(?) wrap - we call it glad wrap or
cling wrap here in oz). Unfortuately we found that TLC plates wrapped in
this stuff leached 14C through and INTO the screen material(yes folks
it wouldn't wash off). As you know 14C has a Looooooong half life and 
therefore the screen are now useless. They can be resufraced at about
2/3 of the cost of a new screen. MD finally confessed to us that some 
other people had had this experience also, but thet didn't think it was
worth letting people who had the machines know. They took no responsibility
for what happened and couldn't even supply the screen to resurface - those
have to be bought directly from Kodak!.

Apart from this our work with th PI has been really good. It is great for 
quantiative work! We have been able to do stuff we never would have been able
to do without it.

As for storage we use an M-O drive from cannon(500MB), but I think there are 
higher capacity ones available now. This way everyone or every lab can have their
own MO cartridge and are therefore responsible for their own data. That way you 
don't have one poor person who is lumped with having to backup others data and 
retreving when they want it. Having the PI on a network like Windows 4
Workgroups or with the new one an  ethertalk net is something worth considering.
As a recomendation, buy the cheapest PI scanner you can and spend the money you 
save on a couple of fast PCs for data precessing.

Hope this is a help.

Mark Smith
Snr Res. Assistant
Dept. Biochemistry
Uni of Sydney
Sydney, Australia
e-mail: mts at

These are my own personal views and not those of Sydney University or the
Biochemistry Department.

More information about the Methods mailing list