Bio-Rad EXQuest Spot Cutter - Manual (Page 528)

Appendix L. Techniques
L-3
Enter a title for the data record next to the Name prompt. You can enter descriptive
information about the calstrip in the Description box.
Next, select the Detection method/stain that was used to make the calstrip.
For Fluorography and Autoradiography detection methods, select the Isotope used.
Also enter the date the calstrip was made next to the Counting date prompt. The
format in which the date should be entered is dd-mmm-yyyy (e.g., 01-Nov-1993 or
01-11-1993). The first three letters of the name of the month or the number of the
month may be entered.
Specify the units for the quantitative values by clicking on one of the buttons next to
the Units prompt or typing the units in the text box next to the Other button.
Finally, enter the Segment values for each segment of the calstrip. These values
should correspond to the calstrip segments as they appear from left to right (i.e., if the
darkest segments are on the left, the values will decrease).
Range of Segment Values and Spot Quantities
The range of segment values should be approximately 2.0 to 2 x 10
4
. The minimum
value the Calstrip Record will accept is 2.0. A typical maximum is 2 x 10
4
, but this
value may vary. The range should span four orders of magnitude.
Typical spot quantities will range from 10
-2
to 5 x 10
3
, depending on the size of the
spot.
An example of segment values (DPM/cm
2
) for an 35 S calstrip are:
Segment #: 1. 278579.0 7. 14892.0 13. 827.0
2. 159376.0 8. 9207.0 14. 516.0
3. 100299.0 9. 5791.0 15. 315.0
4. 67078.0 10. 3670.0 16. 134.0
5. 40895.0 11. 2220.0 17. 93.0
6. 24686.0 12. 1396.0 18. 44.0
Such a calstrip will produce spot quantitation values that typically range from 2.4
DPM to 502.6 DPM.
If you are working with Coomassie gels and you want to make a calstrip, you should
begin with a stock solution and make approximately 10 serial dilutions, each of which
will be used to make one segment of the calstrip.