General Remarks On The Operational Procedures - Thermo Scientific Vitrobot Mk IV User Manual

Chapter | Troubleshooting
The dew point (= temperature) and osmotic effects of water evaporation can be prevented by
using the humidifier to obtain a relative humidity > 99 %. Concentration of particulate material,
inherent to conventional cryo-preparation (and not necessarily a disadvantage), is virtually
absent (or slowed down) when preparation is carried out at water saturating conditions.
Increasing the concentration/density of the material may be necessary to obtain a useful
vitrified specimen with chamber conditions at an rH > 99 %. Under these conditions it is the
blotting that determines the initial thickness of the thin film; further thinning will occur during
the drain process. Gentle and reproducible blotting as performed by the Vitrobot
tailored (e.g. blotting time, number of blotting actions) to the requirements of the specimen,
when an even film is obtained, the thickness can be optimized by choosing an appropriate
drain time (e.g. 10 sec).

4.2 General Remarks on the Operational Procedures

One should abide by the rules of the laboratory and local authorities to secure safe working
conditions. The Vitrobot
operated by trained personnel only. Operation of the Vitrobot
the vitrification process.
The instrument operates only by (build in) PC control. Check PC screen (messages) and
connections before starting an experiment. For temperature and humidity equilibration some
20-30 minutes are required (also see test read-outs provided with the instrument).
Experiments performed at high humidity require sufficient water in the water container. If the
humidity fails to reach the set value (normally within 1-4 min.) check the water level first.
Increasing the relative humidity in the chamber will affect the temperature and for critical
experiments an additional period for thermal equilibration is thus required. Do n ot switch on
the humidifier before the desired temperature has been reached.
Remember that a sample in a vial takes more than 20-30 minutes for thermal equilibration
within the chamber. Pre-heating (incubator, water bath) is recommended for critical sample s.
Blotting papers ( 55 mm with hole) should be mounted at an early stage in the procedure.
Replacing the blot papers when putting a new sample in the chamber is a good routine to
prevent unnecessary opening of the chamber. Make sure that the concave side of the paper is
put against the blot pads. The filter papers are fixed against the blot pads with the white clip
ring.
Excess of ethane in the central cup (a meniscus appears outside the horizontal plane of the
cup) may be removed with some filter paper.
Special applications
On the web-site
applications. Please consult the website.
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PN 103261 | Revision D | 23-Oct-2019
has been designed for use in a fume hood exclusively and is to be
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procedures are given for some special
has to be
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requires basic knowledge of
User Manual
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