Sectioning part: II freehand

Although a double edged razor of the type sold for shaving is best for free-hand sectioning, owing to its more stringent manufacturing controls and increased thinness, for initial attempts a single edge utility razor blade is recommended. The thicker blade and single edge contribute to a sense of safety on the part of the nervous practitioner. In either case, the process is the same. One should first toss out any thought of force or slow pace.

For this example a pine needle is firmly pressed against a glass slip with the nearly vertical thumb of one hand. The glass slip is oriented on a slight angle, such that it is in line with the arm which is owner of thumb holding the pine needle against the slide. The reason for this orientation is that it permits the other arm, and the hand which will be holding the razor is easily brought at a right angle to the other. The position of the arms being important as it is the shoulder and elbow of the blade holding arm that will be moved to make the cut. Using the long bones of the arm as something of a pendulum contributes to the smoothness of a cut section and uniformity of thickness. A chopping cut, or wrist controlled section is sure to be too thick, or horribly distorted.

With a drop of water or two introduced to the slip the needle is first trimmed to expose a cut surface. The blade is then placed so that its flat surface is against the thumbnail of the opposite hand. As the arm holding the blade is drawn backwards the blade is allowed to cut a section. Although the blade should be held firmly force should not be applied to make the cut, allow the shard edge to do the work. Any likely sections may be left of the slip or transferred to a second slip for inspection on the microscope. In either case one should not allow the sections to dry out.

I have never acquired the skill for making a good free hand section, but have managed workable results when making cursory examinations of objects I’ll later section with my B&L sledge style microtome. Here are a few images of comparatively “good” results.

One can see that I managed a reasonable thin section but failed as regards uniformity. This is not clear by examining the sections with the naked eye but is glaringly obvious on the microscope. The probable reason for this is down to my not holding the razor perfectly vertical. I’m satisfied with the work of two minutes as compared to the days labor of processing a specimen for the microtome.

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