Hoefer GD2000 - Manual (Page 23)

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Step 5: Create a vacuum seal
Ten seconds after you set the timer, the vacuum
starts automatically if it is connected through
the vacuum receptacle on the dryer. Watch for
a seal to form between the rubber overlay and
the platen.
If the seal does not form almost immediately,
check stack for misalignment. No materials
should extend beyond the edge of the recess.
Assist seal formation by pressing gently at each
corner to ensure that the rubber sheet is pulled
into the recess.
Without removing the rubber sealing sheet,
periodically inspect the gel as it dries. When the
gel appears dry, check the temperature of the
gel by briefly touching the sealing sheet over the
gel. Wet gels feel cold compared to the platen.
Typically, the gel is dry when the drying surface
has become evenly hot. A markedly flattened gel
contour also indicates that the gel has dried.
In automatic mode, when the set time is reached,
the dryer beeps once and the heater turns off.
The vacuum power remains on for 10 minutes.
During this cooling down period, the Elapsed
Time display counts from “C:00” to “C:10”.
After ten minutes, the vacuum power automati-
cally turns off and the dryer beeps once.
Step 6: Disassembly
Remove each layer of the drying stack and clean
the dryer according to instructions in “Care and
maintenance” on page 17.
Note: If using a cold trap with
inline valves, close the valve
between the trap and gel dryer and
then open the valve between the
trap and the pump. After the trap
is pumped down, open the valve
to the gel dryer. The extra vacuum
should quickly pull the sealing
sheet down and accelerate the
sealing process.
Important! Once the gel has begun
to dry, do not break the vacuum
seal until the gel is completely dry.
Gels may crack if you turn off the
vacuum before the gel is dry.
Note: Some gels may curl as they
dry. To minimize curling, the
vacuum continues for 10 minutes
after the heating timer shuts off.
Note: If you manually turn off the
vacuum during a continuous run,
the heat remains on until you also
turn it off manually.
Note: If the gel contains
radioactive materials and was
covered with plastic wrap,
dispose of the wrap according
to local regulations pertaining to
radioactive waste.
Note: Fluorescent compounds,
such as ethidium bromide, cannot
be visualized after drying.