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2.2
Installation of the Mikro-Dismembrator S
The Mikro-Dismembrator S can be operated on standard
laboratory benches.
Please note:
•
Shaking movements cause the device to vibrate. The
attenuation by suspension of the shake drive and the
support bases cannot completely prevent the vibrations
from being transmitted to the assembly base.
•
Particularly in the case of very high vibration
frequencies or self-resonance of the housing and the
assembly base, the Mikro-Dismembrator S may travel
across the table.
1.
Place the Mikro-Dismembrator S on a solid surface, able
to hold the weight of the equipment and to compensate
any vibrations. Make sure that other equipment in the
vicinity cannot be impaired by the operation of the
Mikro-Dismembrator S.
•
Dimensions:
W x H x L = 297 x 259 x 205 mm
•
Weight:
19 kg
2.
To improve stable standing of the Mikro-Dismembrator
S during operation you may place the unit on to the
rubber pad delivered with unit.
The reciprocating action of the connector with the
shaking flask transmits vibrations to the unit and to the
laboratory bench. These vibrations cannot be fully
compensated by the construction of the drive system
and the rubber stands. Especially at high shaking
frequencies or at self resonance of either the
homogenizer or of the laboratory bench, resonance
effects may force the homogenizer to move over the
working place.
3
Operating Information
3.1
Preparing the Samples, overview
1.
Determine a sample volume depending on the
requirements of the subsequent assay and the method
of processing the sample (grinding, rough disruption,
homogenization or mixing, etc.).
2.
Select a suitable shaking flask and accessories required
(grinding balls, etc.).
•
For grinding of soft material you can use PTFE or steel
flasks and balls made of PTFE or quarz agate.
- PTFE balls offer low abrasion resistance and cannot be
used for abrasive samples.
- Balls made of quarz agate have a high abrasion
resistance.
- For the preparation for the trace element analysis,
PTFE-covered balls or balls made of quartz agate
(Brazilian agate) are recommended.
•
For grinding of frozen or semi-solid or solid substances
you can use stainless steel flasks and steel balls.
Tungsten carbide balls have a high specific weight and
are very resistant against abrasion (this feature is
recommended for homogenization of abrasive
materials).
•
Tungsten carbide balls are not recommended for he
isolation of RNA
•
For suitable samples (fresh tissues, etc.) you can use
disposable test tubes and glass beads. Glass beads show
average abrasion. They are, however, unsuitable for
treating frozen samples or for preparing samples for
trace element analysis.
3.
Efficient grinding and mixing requires a sufficient dead
volume. Consider their size of the grinding balls and the
corresponding volume. Recommended percentage
portion of a sample volume is 30 ... 40 % of the filling
volume.
•
Optimum percentage volumes of sample material, the
grinding balls and the dead volume depend on the
sample material. This has to be determined
experimentally.
4.
If required, add the appropriate buffer solution for wet
grinding or silica sand or a dispersing agent. These
process materials can speed-up the homogenization or
prevent coagulation of the treated sample.
5.
For tough substances (leather, rubber, plastics, etc.), you
can freeze-dry the sample material or freeze it in the
shaking flask. For this you may dip the sample and/or
shaking flask into liquid nitrogen, for instance
("brittle fracture technique", BFT).
•
For specific or more detailed information refer to the
examples for applications in chapter 5 as well as to
material data in chapter 6.
9
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