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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 What is the appropriate pressure of the heated lid?
A5
The lid will need to be adjusted for the height of each different type of consumable used in the
unit. Firstly, with the lid in the down position, turn the orange rotating knob anticlockwise until it
will not go any further. Next with the tubes or plate in the unit, lock the lid and turn the knob
clockwise until pressure on the tubes or plate is just felt; then rotate another quarter turn. Do not
over-tighten.
If you require further technical or applicational assistance please contact Techne at:
For servicing information please contact:
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:
ADDITIONAL INFORMATION
Brief fault finding notes and a list of replacement parts are given in this section.
Note that this equipment should only be dismantled by properly trained personnel. Removing the outer
cover exposes potentially lethal mains voltages. There are no user serviceable parts within this equipment.
FAULT FINDING
Should you have any problems with your TC-412 which cannot be easily remedied, you should contact
your supplier and return the unit if necessary. Please include details of the fault observed and remember
to return the unit in its original packing. Techne accepts no responsibility for damage to units which are
not properly packed for shipping: if in doubt, contact your supplier, giving the full serial number of the
unit and software version number (shown when the unit is first switched on).
FUSES
If neither the power light nor display on the front panel is lit, one of the two fuses may have blown.
Check that there is no external cause, such as a faulty plug or lead. Check both fuses and replace the
faulty fuse with a new one of the correct value (fuse values are given on the label next to the power inlet).
Note that fuses should only be replaced by a qualified electrician.
The holder for the two fuses is built into the mains input socket. First remove the power cable and then
gently prise the fuse drawer open with a flat-bladed screwdriver or similar tool.
Each fuse can be removed by using the screwdriver as a lever.
TC412 Techne Manual 19/12/08 3:38 PM Page 49
