Techne TC-3000X - Manual (Page 51)

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SOME FREQUENTLY ASKED QUESTIONS
Q1 What is the 'Pause' function at the start of the program used for?
A1 Some users prefer to preheat the heated lid before placing the samples into the unit. The pause
feature is used to stop the unit after the 4 minute heated lid preheat step. It will also sound an
audible alarm indicating that the machine is ready for the sample tubes or plate to be added.
Pressing the "Pause" key followed by the "Enter" key will commence the remaining program.
Q2 Why do you have to press some keys twice to make the unit do what you want it to do?
A2 With many of the program features there is a fail-safe function which asks if you are sure you want
to perform a particular action. You are required to press one key to select a function followed by a
second to accept it.
Q3 What is 'Hot Start'?
A3 A "hot start" is used for reducing non-specific product formation during the first cycle of
amplification. The 'Hot Start' programming step is used to pause the instrument at a specific
temperature, typically around 70ºC, after the initial template denaturation. The reason is to allow
the manual addition of unmodified Taq DNA polymerase which may loose activity if added during
the initial 5min denaturation. Heat-activated Taq or Hot Start enzymes do not require this step.
Q4 What is the incremental function?
A4 Incremental timing and temperature are used to increase or decrease either the time or temperature
incrementally over the number of cycles in a stage.
Incrementation of extension time is used with 'Long PCR' which is when large template fragments
are to be amplified (e.g. 27kb lambda DNA, 40kb genomic DNA).
Decremental temperature is used for protocols such as 'Touchdown PCR' where one starts with a
high annealing temperature in the first cycle and gradually decreases the temperature over the
number of cycles in the stage. This ensures that only the specific product is amplified.
Q5 The heat-up ramp-rate in the specification is 3.6°C/second yet I can only manually set it to
2.0°C/second. Why is this?
A5 If you set the ramp-rate to max the block will heat at 3.6°C/second the unit sets its own control
parameters. If you program a ramp-rate the control parameters reduce the ramp-rate. This is a
feature of the software and not the actual ramp-rate.
If you require further technical or applicational assistance please contact Bibby Scientific Ltd at:
[email protected].
For servicing information please contact: [email protected].
We are continually striving to improve our thermal cyclers and software. If you have any comments and
suggestions on how we can do things better please send them to us at:
[email protected]