Bio-Rad CHEF Mapper® XA System - Manual (Page 35)

It is not necessary to press CLR ENTRY before entering a new value. If you make a mis-
take while entering a new value, press CLR ENTRY, and make the correction. To move the
prompt from one parameter to another while in the edit mode, use ENTER or any of the four
cursor arrow keys. If you make mistakes entering values while in the edit mode, use the cur-
sor arrow keys to go back to the mistake and correct it. When editing run times, interrupt
frequencies, interrupt length, initial switch times, and final switch times, enter the numeric
value first, then HOURS, MINUTES, or SECONDS. To leave the edit mode, use ENTER, the
down cursor arrow key, or the right cursor arrow key to move the prompt to the end of the pro-
gram.
There are three methods for entering the edit mode during a run. Stop the run with STOP
RUN, press the comma key for 6 seconds during a run, or pause the run, then press the comma
key for 6 seconds. All of these methods will display the message You will destroy last
program - Go on?. Enter 2 for edit, then press ENTER. This will take you to the first prompt
in the program.
Note: Run time cannot be edited during a run. Run time can be edited only before the
run is started.
Section 5
The Auto Algorithm Mode
5.1 Operation
The auto algorithm is embedded in the microprocessor in the CHEF Mapper XA power
module. The auto algorithm calculates the optimal switch times, switch time ramp, field angle,
voltage gradient, and run time for the DNA molecules in your sample. The run conditions set
by the auto algorithm place the smallest DNA fragment specified approximately 9 cm from the
origin of an agarose gel. The fragments specified may be in your sample or a size standard.
To access the auto algorithm mode, press AUTO ALGORITHM . The following screen
will appear:
This screen is used to establish the size range of DNA to be separated.
Low: Enter the size of the smallest DNA fragment, press K-BASES or M-BASES, and
ENTER.
High: Enter the size of the largest DNA fragment, press K-BASES or M-BASES, and ENTER.
Note: The limits of the auto algorithm are from 1 kb to 6 mb. Any entries outside these
limits will not be accepted. If the number entered in high is greater than 6 mb, the screen
will display Auto Algorithm Error - Large DNA too big - Press ENTER. Press
ENTER to return to the screen displaying Please enter another command, and press
AUTO ALGORITHM to re-enter values within the limits of the algorithm. If the high
size is less than the low, the CHEF Mapper system will automatically reverse them.
When you press ENTER after entering the high DNA fragment, the screen will display
the following:
Molecular weight Low [ ] High [ ]
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