How to get sections from the finest objects: About razor blades, elder marrow and bottle corks

The first steps into science are not too difficult. If a microscope is at hand, the preparation of the sample is the key issue.

Nature gives us an easy entry. Egeria densa (Elodea densa) an American/Canadian waterweed, is an aquarium plant you can buy in every pet shop. A cheap and quick purchase.

Egeria Densa (Source)

The leaves are transparent as they only have 2 cell layers. Pull off one complete leaf from the stem and cut out a small portion. Place it onto a glass slide, add a drop of water and cover the sample with a cover slip.

© Sabine Lask, Heidelberg, (Germany)

© Sabine Lask, Heidelberg, (Germany)

The movement of the chloroplasts along the cell walls is easily visible and the phenomenon can be documented, even with a smart phone without special eyepiece adapter attached to the eyepiece tube. 

© Sabine Lask, Heidelberg, (Germany)

If it comes to a cross section of a leaf, a root or a moss stem we need further equipment. Two tweezers would be fine, a sharp needle helps in any case to pick up a tiny piece. To sharpen the tips of our instruments, a grindstone is recommended.

Tweezers, a preparation needle

Grindstone

The Common Elder (Sambucus nigra) with its shoots from the previous year delivers an excellent material to hold delicate material. Pull away the bark with your fingernails, extract the dry marrow and keep it for the rest of your botanical life.

The golden rule for any embedding material is as follows: The embedding material should have a similar hardness as the sample to be cut.

Commom Elder (Source)

Elder marrow, bottle cork

Elder marrow is for soft materials, a bottle cork is suitable for hard material like seeds or lignified stems.

For sections, an old school razor blade like this is the best choice:

©Sabine Lask, Heidelberg, (Germany)

I suggest to have the embedding material, place the sample in between and clamp it. The first cut is just to flatten the cutting surface.

© Emily Gspandl, Heppenheim, (Germany)

Take the razor blade between thumb and forefinger and move it without any pressure in a diagonal direction towards yourself, similar like cutting a bread in the good old times. Similar, but not identical: Do not move the razor blade back and forth, pull it smoothly towards yourself. With a little bit of experience, successful results are quite probable.

Cross section of leaf Helleborus niger (by 11-years-old child)

©Sabine Lask, Heidelberg, (Germany)

You need a surface section to have a look on the stomata (“breathing openings”) of a leaf? Wrap the leaf around your forefinger and use the razor blade in the described way.

©Sabine Lask, Heidelberg, (Germany)

The analogue reconditioning:

Surface section of leaf Helleborus niger ©Sabine Lask, Heidelberg, (Germany)

Again, the first steps towards science are not that difficult. Take your time, relax, for grown-ups: receive patience from the suppling device of your corks.

One more message we need to say: It’s time so supply all schools with adequate microscopes and suitable cameras. For better images, for a better teaching.