Lect 'es

Tools for clean preparation of biological samples (reference materials)

S. Szymczyk and M. Cholewa Institute of Nuclear Physics, ul. Radzikowskiego 152, PL-31-342 Cracow, Poland

Summary. Tools made of corundum single crystals (A1203) grown artificially were found to be excellent for clean prepa- ration of biological samples. Scalpels and knives made in cooperation with the Metallurgical Works at Skawina are described

from the Department of Synthetic Stones. We are using the biological scalpels without handles because they can thus be cleaned more easily. However, the Metallurgical Works Skawina, in cooperation with medical institutes, also pro- duce a microsurgical scalpel (Fig. 2), which is very conven- ient, for instance, in ophthalmic operations just because of

Introduction

Sophisticated methods (e.g. PIXE or SRIXE) help to per- form trace element analysis with great sensitivity from a few ppm to ppb, with multielement capability for small sample size and low degree of radiation damage. This cannot be matched by other analytical methods for elemental analysis in biological materials. However, handling the samples with metallic tools such as knives, stirrers, etc. may cause contamination. We therefore found it necessary to avoid any contact of the specimens with such metallic objects. Clean preparation of the standards (eg. NBS or IAEA) available on the market and of the samples for microbeam analysis is of great importance.

In cooperation with the Metallurgical Works Skawina we developed and tested some tools made of artificially grown corundum single crystals.

Specific properties of corundum

Corundum is an aluminium oxide A1203 with small admixtures of chromium, titanium or iron. Its colour depends on the chemical admixtures. Colourless crystals are chemically extremely dean. Corundum does not melt in the flame and is not dissolved in acid. Its hardness is 9 in Mohs' scale. It is the hardest mineral after diamond, with very high resistance to mechanical action. Fine-crystalline forms are used as abrasive (emery) and polishing material. Colourless corundum is called white sapphire or leucosapphire.

Scalpels for clean preparation of biological samples

In cooperation with the Metallurgical Work Skawina we developed and tested the so-called biological scalpels. In our opinion they are very useful in preparing different samples for trace elements analysis. Four shapes are presented in Fig. 1 : their dimensions are: length 30 rim, width 12.5 mm, thickness 2 mm. Other shapes and sizes may be ordered

Offprint requests to: S. Szymczyk

Fresenius Z Anal Chem (1987) 326: 744 -- 745 �9 Springer-Verlag 1987

CHISEL WITH C, VMMETRIC

CUTTING EDGE

CHISEL WITH ASYMMETRIC

CUTT•G EDGE

Fig. 1. Biological scalpels

LENGTH WITHOUT r 85mm LENGTH a/BLADE 2 m m

THICKNESS 0.5/am WIDI"H OF CUTTING EDGE t.t, mm

MATERIALS : BLADE- CORUNDUM HANDLE-TITANIUM BLADE TIP COVER-TEFLON

Fig. 2. Microsurgical scalpel

1 t

KNIFE WITH SLANTING

SYMMETRIC CUTTING EDGE

KNIFE WITH SLANTING

ASYMMETRIC CUT TING EDGE

P@r se

its handle. It is made of titanium and is therefore durable and easy to sterilize. These scalpels have been used for eight years and proved be excellent.

Conclusions

Scalpels made of leucosapphire offer advantages: I. they avoid contamination of the samples, 2. they cut the tissue gently,

the following

3. they allow observation of that part of the tissue which is under the transparent blade,

4. they may be easily sterilized in autoclaves and sterilizers.

Acknowledgement. We are very grateful to Mr. Jan Osocha, MSc, for his technical assistance during the experiments and to the staff of the Metallurgical Works Skawina for preparing the corundum tools.

Received September 15, 1986

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