Leica Biosystems ANGLE TWO - Manual (Page 44)

Using the Instrument
Leica Angle Two ™ User Manual Rev A02 © Leica Biosystems Richmond Inc. 2010 44
11. Support the head and insert the right ear bar into the right ear.
12. Lower the right ear bar into the instrument and lock it in place.
13. Check that both ear bar scales have the same readings.
If not, loosen both ear bar locks and move the animal until both scales agree, then relock.
14. Check that the ear bars are fully inserted in the ear canals. There are two tests for this:
(i) gently push the nose side to side;
(ii) swivel the nose up or down about the earbars.
If the nose has any side-to-side movement or returns to its original position after you move it
up or down, the ear bars are not in the ear canal with stable hold. Reinsert the ear bars,
repeating these instructions from step 10.
15. Gently move the animal’s nose from side to side and up and down to check the ear bars are
correctly positioned:
If the nose moves reposition the ear bars further inside the ear canal. Ensure the ear bars have
the same reading.
Installing the Incisor Bar and Nose Clamp
16. Slide the incisor bar into the animal’s mouth and hook the incisor teeth over the bar.
17. Push the animal’s nose down, and slide the bar away from the animal so that the bar is directly
behind the incisor teeth.
18. Tighten the horizontal thumbscrew (see Figure 5), so the bar cannot move.
19. If using an injectable anesthetic lower the nose clamp so it is secure against the animal’s nose.
If using gas anesthetic remove the nose clamp and install the nose cone.
Locating Bregma and Lambda
After the skull is exposed locate the bregma and lambda points and mark them. We recommend
using the video microscope or a stereomicroscope to accurately determine each point and reduce
error.
The bregma and lambda points are used by the software to calculate the distance the manipulator
must move along each axis to reach the target site. As well, the bregma and lambda points provide
the variance angle of the animal’s skull from flat (0°), which is corrected for by the software so no
manual adjustment of the instrument is needed.
NOTE: Always position the probe at the bregma point first.
To identify the bregma and lambda points to the software:
20. Place the probe on the marked bregma point and click ‘at Bregma’. The Atlas mode will open
showing the probe’s coordinates.
21. Reposition the probe tip at lambda and click at Lambda. The Skull box displays the skull’s
angle of variance from flat (0°).