Bio-Rad PDQuest 2-D Analysis Software - Manual (Page 23)

2.12 Cutting Tip Height
• Place the cutting mat and protective gel sheet on the cutting platform.
• Click the "Set Cutting Tip Height" icon in the Set up area of the "Basic Excision Tool"
dialog box to move the cutting head to the middle of the cutting platform and the "set
cutting height" dialog box appears on the screen.
• From the "Set Cutting Tip Height" dialog box, use the "lower head" command to assess
how far down the cutting tip goes. The cutting tip should lightly push down onto the
protective gel sheet. If the cutting tip is too high off the cutting mat or too far down into
the cutting mat adjust the cutting tip height using the following steps:
1. Loosen the set screw in the gold Spindle Hexagonal Screw at the top of the cutting
shaft. This set screw is accessed through the hole in the head cover, as indicted in
the photo, Figure 16a. If you are having difficulty finding the set screw inside, take the
black cover off by removing the two 2.5 mm screws inside the cover. You will then
see the cutting head as Figure 16b.
Fig. 16a. Set cutting tip height with cover Fig. 16b. Cutting head.
on.
2. With one hand, hold the lower part of the Spindle Cutting Assembly. With the other,
Adjust the height of the silver cutting shaft by moving the shaft up or down as
required.
3. After adjustment, tighten the set screw to "snug" but do not overtighten. Damage
can occur to the cutting shaft if the set screw is overtightened. The set screw must
be tightened before a test cut is made at the new height.
4. When the tip depth is correct, use the software command "Raise tip" and then "Test
Cut" to test the cutting depth. A wetted piece of PVDF membrane on the platform
works well for this test.
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