Gradient Thermocyclers

[J.C. Abbott]

Alan Nighorn <nighorn at manduca.neurobio.arizona.edu> wrote in article
<Pine.SUN.3.91.970125134342.6634A-100000 at manduca.neurobio.arizona.edu>...
> 
> 
> Hi folks,
> 
> We are considering the purchase of a gradient PCR machine to
> help optimize our PCR reactions. We were wondering first who makes
> them ? And second, we wanted to know if anyone has any experience with
> their reliability. Are they subject to frequent repair?

Our lab has recently bought a Robocycler 96 from Stratagene. This is a
gradient cycler which has four separate blocks held at different
temperatures. Instead of ramping the temperature, a motorised arm moves
your tubes between the different blocks, making runs about 30% quicker. The
gradient feature has already proven it's worth, after a PCR using
degenerate primers worked at only one annealing temperature, even though
five temperatures were used. We had a result in an afternoon which would
probably have taken a week of experimenting otherwise.I believe Hybaid have
alsointroduced a gradient cycler, which comes in considerably cheaper than
the robocycler. 

Although we have only had our cycler a short while, we are now on our
third. That may sound a bit misleading regarding reliability, since the
first model we tried was a *very* hammered demo model (i.e. dents in the
side of the case), while the second, which we bought, developed a noisy
rotor arm, but was changed immediately by Stratagene. We have been running
the third for about a month now, and so far it is holding up....

Wether the additional expense, and complexity (i.e. more to go wrong), of
the Robocycler is worth the decreased run time depends on how much you use
it. 

Hope this is of some use.


--------------------------------------------------------------------------
J.C. Abbott,
Department of Biological Sciences,
Millers Wynd,
University of Dundee,
Dundee,
DD1 4HN
--------------------------------------------------------------------------
email jabbott at dundee.ac.uk
fax work        :-  +44 (1382) 344275
phone work  :-   +44 (1382) 344750 
           home :- (01382) 647180 ext. 1019
---------------------------------------------------------------------------