DiATOME Ultra Sonic Oscillating Diamond Knife

The DiATOME ultra sonic, the oscillating diamond knife for room temperature ultramicrotomy. It was developed in collaboration with Dr Daniel Studer, Lab. of Anatomy, University of Berne.

A piezo actuator produces an oscillation of the knife at a desired frequency and amplitude, parallel with the cutting edge. A depression in the foot of the knife allows the oscillation parallel to the cutting edge. The depression is rigid in the north/south direction and guarantees stability in the cutting direction.

The new knife produces ultrathin sections almost free of compression.The sections become thinner at the same thickness setting: since the volume of the section remains the same, the increased length leads to a decrease in thickness.

The theoretical considerations and first results of this invention were presented in the Journal of Microscopy (Ref 13). Results with polymers using the oscillating knife were shown at the M&M 2002 meeting in Quebec (Ref 14).

We have tested the oscillating knife with the following samples:

• Biological samples in Epon, Araldite, EM Bed, etc.
• Biological samples in acrylic resins (Lowicryls, LR White).
• Rigid polymers such as PS, PMMA, ABS, HIPS, modified PP, etc.

Picture 1 (71 kb) Peripheral nerve (rat)

Picture 2 (46 kb) Heart (rat)

Picture 3 (40 kb) Human keratinocyte

Picture 4 (69 kb) ABS

Picture 5 (79 kb) Impact modified PP

Specifications

• Knife angle: 35°
• Knife cutting range: 10-80nm
• Knife cutting edge length: 3.0mm

Control Unit

• Frequency: 25-45kHz, or automatic setting of the resonance
• Amplitude: variable (Voltage 0-30V)
• Mains voltage: 230V, 110V

References

1. H. Sitte: Advanced Instrumentation and Methodology related to Cryoultramicrotomy: a Review. Scanning Microscopy Supplement 10, pp. 87-466, 1996.
2. M. Michel, H. Gnägi and M. Müller: Diamonds are a cryosectioner's best friend. Journal of Microscopy, Vol. 166, Pt 1, pp. 43-56, 1992.
3. O.L. Reymond: The diamond knife "semi": a substitute for glass or conventional diamond knives in the ultramicrotomy of thin and semi-thin sections. Bas. Applied Histochemistry, No. 30, pp. 487-494, 1986.
4. Various publications on materials ultramicrotomy. Microscopy Research and Technique, Vol. 31. Number 4, pp. 265-310, 1995.
5. L. Edelmann: Freeze-substitution and the preservation of diffusable ions. Journal of Microscopy, Vol. 161, pp. 217-228, 1991.
6. J.C. Jésior: How to avoid compression. Journal of Ultrastructure and Molecular Structure Research, pp. 210-217, 1986.
7. J.C. Jésior: Use of low-angle diamond knives leads to improved ultrastructural preservation of ultrathin sections. Scanning Microscopy Supplement 3, pp. 147-153, 1989.
8. K. Richter: Cutting artefacts on ultrathin cryosections of biological bulk specimens. Micron, Vol. 25, No. 4, pp. 297-308, 1994.
9. K. Richter, H.Gnaegi and J. Dubochet: A model for cryosectioning based on the morphology of vitrified ultrathin sections. Journal of Microscopy, Vol. 163, Pt 1, pp. 19-28, 1991.
10. C.E. Hsieh, M. Marko, J. Frank and C.A. Mannella: Electron tomographic analysis of frozen-hydrated tissue sections. Journal of Structural Biology 138, pp. 63-73, 2002.
11. J.R. McIntosh: Electron Microscopy of Cells: A new beginning of a new century. The journal of Cell Biology, Vol. 153, pp. 25-32, 2001.
12. A. Al-Amoudi, J.Dubochet, H. Gnaegi, W. Lüthi, D.Studer: An oscillating cryo-knife reduces cuttinginduced deformation of vitreous ultrathin sections. Journal of Microscopy, Vol. 212, Pt 1, pp. 26-33, 2003.
13. D. Studer and H. Gnägi: Minimal compression of ultrathin sections with use of an oscillating diamond knife. Journal of Microscopy, Vol. 197, Pt 1, pp. 94-100, 2000.
14. J.S. Vastenhout and H.Gnaegi: Ultramicrotomy of polymers using an oscillating knife; improving polymer morphology. Microscopy and Microanalysis. 8 (Suppl. 2) 2002

What services can we offer you?

• Technical assistance in all fields of ultramicrotomy.
• Free sectioning tests for all types of samples.
• Make use of our many years of experience in perfecting our knives.
• With a telephone call, an e-mail or a fax message we can inform you of any details you require.

We are looking forward to hearing from you soon!

Your DiATOME Team

Ultra Room Temperature Diamond Knife