Techne TC-512 - Manual (Page 39)

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The Hold Temperature of the incremented/decremented step is the defined Hold Temperature plus the
summation of the increments/decrements. The first cycle is never altered, only subsequent cycles. If
decrement is selected, the Hold Temperature is prevented from falling below 4°C. If increment is
selected the Hold Temperature is prevented from rising above 99°C.
Similarly, under normal circumstances, the Hold Time of all steps is constant. However, it is possible to
automatically increment or decrement the duration of a specified step of a programme. When
amplifying large fragments of DNA it is necessary to ensure that the extension is fully complete after
each cycle, so the extension time is increased with each cycle to compensate for the increased product
quantity and decreasing concentrations of reagents.
The Hold Time of the incremented/ decremented step is the defined Hold Time plus the summation of
the increments/decrements. The first cycle is never altered, only subsequent cycles. If you select a
decrement, the Hold Time is prevented from falling below one second.
Cycle 1 Cycle 2 Cycle 3 Cycle 4
- i
- i
- i
Time
Temperatur
e
Cycle 1 Cycle 2 Cycle 3
Time
Temperatur
e
Decremental temperature for
Touchdown DNA amplification
Incremental time for amplification
of long DNA products
TC512 Techne Manual 19/12/08 3:30 PM Page 39