Bio-Rad Profinia™ Protein Purification Instrument - Manual (Page 45)

• A
280
of 1 mg/ml — extinction coefficient for the protein expressed as the absorbance of
a 1 mg/ml solution of the protein of interest at 280 nm for a 1 cm UV pathlength. The
default value for this parameter is 1.00. An extinction coefficient can be assigned for
each sample. This value is used to calculate the estimated total protein and protein
concentration at the end of the run. An extinction coefficient converts absorbance units
(AU or OD) to concentration units (mg/ml). For example, if a protein has an AU of 1.38,
and an extinction coefficient of 1.25 AU/mg/ml, the concentration of that protein solution
is calculated as 1.38 AU/1.25 AU/mg/ml = 1.1 mg/ml. The Profinia firmware uses this
algorithm to calculate protein concentration and yield from the absorbance units under
the purified peak.
Note: If you measure the absorbance of your protein with a short-pathlength cuvette, you
must multiply the absorbance value to normalize to 1 cm. For example, the absorbance
measured in a 2 mm cuvette must be multiplied by 5. This value is then entered for A
280
of
1 mg/ml.
• Home — returns to the home screen. All entered run and sample information, except
lot number tracking information, will be cleared when you select the Home button. The
entered lot number tracking information remains in temporary memory as long as
instrument power is on. When cycling power, lot number tracking information defaults to
“BLANK”
6.4.1 Adding or Editing Run and Sample Information
To add or edit sample and run information:
1. Touch the arrow buttons to the right of the information text box to scroll through the list
of options and highlight the parameter for which you’d like to add information.
2. Touch the Edit button to access the alphanumeric or numeric keypad. The appropriate
keypad displays.
3. Enter or edit information for the selected parameter in the text line at the top of the
screen.
Note: If values entered exceed the system-set limits, the value limits appear immediately
below the text line of the numeric keypad and the system overrides the entered value with
the maximum or minimum value allowed.
4. Touch OK to accept all changes or Cancel to delete any entered data and return to the
Enter Run & Sample Information screen.
5. Repeat this process for all information parameters. For details on entering lot number
tracking, see section 6.4.2 below.
Note: Touch the Clear All button to delete the text or data entered into the text line. The
default “UNTITLED” text can be cleared with any keystroke.
6.4.2 Adding Lot Number Tracking Information
To add lot number information for any of the reagents or components used in your method:
1. Use the arrow buttons to the right of the information text box to scroll through the list of
options and highlight “Lot # Tracking”.
2. Touch the Edit button. You will proceed to the Edit Lot Number Information screen
(Figure 6.9).
38