Bio-Rad Components for Older Model Spot Cutter - Manual (Page 14)

This target is also useful for focussing the lens during installation, re-calibration, or for
checking the image acquisition in UV or white light modes.
3.4 Checklist for Operation in White Light Mode
1. Toggle the black switch on the back of the ballast box on the spot cutter to the white light
position. See Figure 16 for location of the toggle switch.
2. Check the white lights by pushing the red “Lights on” button on the lower front right side
of the spot cutter base. If the lights do not come on under the platform, toggle the back
switch to the correct position and re-check the lights.
3. Close the aperture setting to f-stop 5.6 –16, or to the white light/closed position.
4. Remove everything (including the cutting mat) from the cutting platform.
5. Close the Enclosure door if it will be closed during imaging of the actual gel.
6. Open the “Focus cutter camera” icon and click on the “Auto-expose” button to automatically
adjust the exposure setting. Click “OK” on the message “Auto-expose complete” and then
click “Stop”.
7. Select the "Light on (Gel)" setting in either the Basic Excision Tool or the Integrated
Excision Tool screen.
3.5 Calibration
After the Enclosure and Spot Cutter set-up is complete, calibrate the spot cutter. Use the following
checklist to ensure that the calibration is successful.
1. Install the lens bandpass filter.
2. Switch the light toggle switch to the white light setting.
3. Check the white lights by pushing the red "Lights on" button on the lower front right side
of the spot cutter base. If the lights do not come on under the platform, toggle the light
toggle switch to the other position and re-check the lights.
4. Change the aperture setting to f-stop 5.6 –16, or the white light setting.
5. Remove everything from the cutting platform.
6. Close the door of the Enclosure.
7. Click on the "Focus Cutter camera" icon in the Basic Excision Tool screen.
8. Click on “Auto-expose” to reset the exposure time of the white light image acquisition.
Click “OK” for auto-expose complete, then “Stop” to end Focus mode.
9. Click on the "Calibrate Cutter" icon. A message will come up on the screen asking
whether the calibration is to be performed with tth he e lle en ns s ffiilltte err iin ns stta alllle ed d. Click on "L Le en ns s ffiilltte err
iin ns stta alllle ed d". This must be confirmed so that the fluorescent parts of the software will
become active. This is an important step to ensure proper set-up and final accuracy of the
calibration.
10. The rest of the calibration procedure is described in the general spot cutter manual and in
the on-screen instructions for calibration. For optimum accuracy in both the white light
and UV light modes, leave the bandpass lens filter installed for both UV and white light
imaging and spot cutting. Only the aperture setting is changed between light modes. Spot
accuracy will be adversely affected due to refractive index changes if the filter is removed.
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