Agilent Technologies 3100 OFFGEL Fractionator User Manual page 47

Operation 5
Working with Methods
In a pull down menu for Method Selection you can select methods that are
present on the internal drive of the instrument or on the USB stick inserted at
the rear of the instrument. These methods can either be default methods
which were supplied with the instrument or user modified methods. A
3100 OFFGEL fractionators method generally consist out of two method steps
which are the focusing and the hold phase. The methods do not contain the
platform temperature as parameter. During the focusing step, the sample
fractionation is taking place, typically at higher voltages, until a given Volt
Hour value (kVh) is reached or a given Time (h:mm) has elapsed. The hold step
is typically done at lower voltages after the fractionation just to maintain the
achieved separation until the fractions are recovered from the wells.
The Volt Hour value (kVh) or Time (h:mm) are limiting parameters for the
duration of the fractionation. The default methods have values that were
found to be suitable for a broad range of applications and samples. The
parameters Voltage, Current and Power are by Ohms Law in a correlation for a
given fractionation in an individual strip/lane. The Method parameters
Voltage, Current and Power are limiting factors during a run. One of the
parameters, typically current, is at the limit.
Please save modifications before changing to another tab. Changes will be lost otherwise.
N O T E
The focus step of a method can be sub-devided into different time based steps
if desired. Create a time based program using the lower part of the method
tab. A Timetable for the parameters Voltage, Current and Power is visualized
in a graphical way with color coding per value. In case time table entries are
done the parameters set above are used as starting values at time 0:00. Select
the desired parameter, for example voltage, in the timetable pane from a drop
down menu. Set the value in the adjacent field. Changing from one value
setting to another one at a second timepoint can be done as one step or
applied as a linear gradient. The point in time when this change should
happen during the method execution can be given. Press the Add button to
add more method steps. You also can edit any time table entry by highlighting
it. By selecting one line, the corresponding values get populated in the
parameter line. After modifying values you can apply them to the method with
the Set button. The platform temperature is no method parameter and cannot
be changed in the timetable. For changing platform temperature, please see
page 42.
OFFGEL User Manual 47