The Elements Of A Program - BIO RAD PTC-200 Operation Manual

DNA Engine Operations Manual

The Elements of a Program

DNA Engine
steps are run using one of two possible temperature control methods: calculated con-
trol or block control.
Programs may contain five types of steps. Two of the steps are mandatory, and three are
optional:
1. Temperature step (mandatory): Sets a temperature for the block and the length
of time it is held at that temperature. The DNA Engine cycler brings the block to
this temperature at its maximum rate of heating or cooling, unless modifying
instructions are added to the program. (The maximum rate of heating and cooling
is up to 3°C/sec for all single- and dual-block Alpha
Slide Chambers
2. Gradient step (optional): Allows you to program a temperature gradient across
the sample block. The range of any single gradient can be as great as 24°C from
left to right. The maximum programmable temperature is 105°C; the minimum
programmable temperature is 30°C.
3. Ramp step (optional): Sets a slower-than-maximum rate of heating or cooling.
4. GoTo step (optional): Causes the program to cycle back to an earlier step for a
specified number of times (up to 9,999 times).
5. End step (mandatory): Instructs the DNA Engine cycler to shut down its heat
pump because the program is complete.
Additional instructions, termed options, can be added to certain program steps to modify
their effects:
1. Increment: Modifies a temperature step to allow a progressive increase or decrease
of temperature (0.1–10.0°C per cycle) each time the step is executed in a cycle.
This is useful in "touchdown" programs, when the annealing temperature of an
oligonucleotide is not known.
2. Extend: Modifies a temperature step to allow progressive lengthening or shortening of
a temperature step hold (by 1–60 sec/cycle) each time a step is executed in a cycle.
This is useful for accommodating an enzyme with diminishing activity.
3. Beep: Modifies a temperature step or ramp step to make the machine beep when the
target temperature is reached.
6-2 Tech Support: 1-800-4BIORAD • 1-800-424-6723 • www.bio-rad.com
® cycler programs consist of a series of steps encoding a protocol. These
™ Alpha unit.)
™ units; 1.2°C/sec for the