Vibratome® Operation

The principle of the Vibratome® is a vibrating blade intersecting the specimen underneath the surface of a liquid bath which lubricates the cut. There are five parameters under the control of the operator:

1. Nature of the bath (usually a physiologically compatible buffer).
2. Temperature of the bath (the softer the specimen, the colder the bath should be).
3. Speed (the softer the specimen, the slower the speed).
4. Amplitude (the softer the specimen, the higher the amplitude).
5. Blade angle (the softer the specimen, the steeper the angle of attack required).

One must, by trial and error, find the right mix of these parameter settings.

In regard to specific specimens, some starting recommendations are:

Brain

If brain tissue is well fixed, one should be able to obtain 20 or 30 micron thickness without embedding. If brain tissue is fresh, one should be able to obtain 30 or 40 micron thickness without embedding.

General rules for brain:

1. bath- cold (2-6 degrees C)
2. speed- slow (setting 1-2)
3. amplitude- high (>8)
4. blade angle- steep (25 degrees or more)

Liver

1. Liver is about as soft as brain, so the same general recommendations would apply.
2. If embedding is necessary (e.g., fresh brain at 20 microns), do not use agar. Use 2-5% neutral agarose.
3. Always cut section thicknesses in increments of 10 microns (i.e. at the detent "click").
4. Thicknesses less than 20 microns can sometimes be acheived with firm specimens, or by using glass or sapphire blades.