P.E. 9600 thermocyclers-the cooling fix...
Christopher G. Alpha
cga3 at cornell.edu
Mon Feb 3 12:53:25 EST 1997
In article <528emb$3r0 at mserv1.dl.ac.uk>,
"J.P. Hays" <jph5 at leicester.ac.uk> wrote:
>In reply to Clemens Suter-Crazzolara :-
>We too have a Perkin Elmer 9600 PCR machine that is 3 - 4 years old and
we have problems with our machine (especially the cooling system). This
to be a fault with the machine (we don't trust our 9600 for PCR anymore). As
you mentioned the cost of servicing the machine is prohibitively expensive.
All I can suggest is for people to try other (more reliable) PCR machines!
>jph5 at le.ac.uk
We've got the same machines too, running all day and night, and have
experienced chiller failure as well...BUT its just a question (generally) of a
little preventative maintainance every year or so. So have at thee! If you
open up the machine, the cover tilts forward and locks into place, you will
see the fluid pump and reservoir (clear brownish plastic on ours). Inside the
reservoir, the cap unscrews (be careful to note the positions of the parts and
the gaskets), there is a small cup-like filter for the coolant. The coolant
BTW is basic auto antifreeze--20% E. glycol in dH2O, buy something good.
Often the problem when you have chiller failure and the diagnostics indicate
low flow as well--this filter is clogged. It just gets gummed up with
deposits and bits of hose as they degrade over time. If it looks
whiteish/opaque then take it to a sink and gently (its nylon and weak) scrub
it with a test tube brush until clean and water flows thru it ok. Now flush
the system out with dH2O by attaching a tube to the line coming into the
reservoir cap and put the end of this to a beaker. (BE VERY CAREFUL here with
fluids and the electronics put something around the work areas to soak up any
spills from the reservoir etc...) Fill the open reservoir with dH2O and
switch the machine on for a moment BUT DON'T LET THE FLUID LEVEL DROP BELOW
THE BOTTOM OF THE RESERVOIR, otherwise you will lose the prime on the pump and
get annoyed trying to prime it again (if you do: try backfilling the system),
and then switch it off, refill, repeat until clear water runs out. Now flush
the dH2O out with your 20% coolant solution the same way until that runs the
right color. Put all the pieces back in and gaskets seated properly, and
screw the cap on a LITTLE. Leave it loose and turn it on, the level will drop
as air bubbles come out of the system. Turn it off, open it up, top up the
reservoir, and repeat until you are sure its full and don't see any bubbles
(some bubbles may get trapped-so gently tap on things and they'll pop free).
Once satisfied tighten it all up and run the diagnostics again to verify that
either you fixed it or that you have a pump or condenser problem instead...
Plant Genetic Resources Unit
Geneva, NY 14456
anyone need a handy tech out there?
Or hey since it costs at least 800.00 US to have them look at one of
these, ship in to and from me and I'll do it for half, that's right!
HALF!!! (just like some bad commercial, huh?) ;)
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