Bio-Rad Model 785 Vacuum Blotter - Manual (Page 7)

Environmental
Operating 50 °F (10 °C) to 90 °F (32 °C) temperature
30–80% humidity
Storage 32 °F (0 °C) to 140 °F (60 °C) temperature
10–90% humidity
Cautions
1. Not designed to handle liquids or heavy vapors. If pump does get liquid inside, open
valve to max position and let run for 15 minutes to allow interior components to dry.
2. If valve knob loosens up during operation, wrap threads with
PTFE tape to increase
thread engagement.
3. Pump will become hot after a few hours of continuous use. This is normal and should
not be a cause for concern.
Section 2
Description of Major Parts
2.1 Base Unit
The Base Unit is the foundation of the Model 785 Vacuum Blotter. The plastic used to
make the Base Unit is an off-white color with a slight texture. The Base Unit is made of a
durable and chemically resistant mindel-S plastic. In low concentrations, acids and bases 0.25
N HCl or 0.5 N NaOH will not damage the Base Unit or the Vacuum Stage. The Base Unit
supports the Vacuum Stage on springs and catches the transfer solution during disassembly.
2.2 Vacuum Stage
The Vacuum Stage is supported by springs on the Base Unit. The spring action on the
Vacuum Stage is used to lock and unlock the Sealing Frame. The center portion of the
Vacuum Stage has a grooved grid pattern. This grid pattern helps distribute the vacuum
pressure evenly across the Porous Vacuum Plate. In the center of the grid pattern is a
port. This port is the vacuum inlet and is connected to vacuum tubing underneath the
Vacuum Stage. Surrounding the grid area is a soft silicon Reservoir Seal O-ring that
provides a water-tight seal to the upper buffer chamber.
2.3 Porous Vacuum Plate
The Porous Vacuum Plate is a white polypropylene sheet. The Porous Vacuum Plate
is used to support the transfer membrane and the gel. Along with the grid pattern on the
Vacuum Stage, the Porous Vacuum Plate helps distribute the vacuum pressure evenly.
2.4 Window Gasket
The Precut Window Gasket is a green vinyl sheet with a window cut out of the
center. Refer to Section 3.2 for instructions on how to cut the Blank Window Gasket. The
Window Gasket is used to mask off the remaining Porous Vacuum Plate not covered by
the gel. The Window Gasket forces the vacuum through the gel/membrane complex by
making a watertight seal where the gel overlaps the Window Gasket. The Window
Gasket also seals in the vacuum along the Reservoir Seal O-ring when the Sealing Frame
is compressed onto the Vacuum Stage.
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