Bio-Rad BioLogic LP System - Manual (Page 5)

5 4006069 Rev D
Bio-Rad Laboratories, 2000 Alfred Novel Drive, Hercules CA 94547
Care of the Gradient Mixer’s Proportioning Valve
Normally, the only maintenance required is to flush the valve with water. Use the Econo Gradient
Pump’s Manual mode to set the buffer to 50%B and place both inlet tubes in a vessel of water and pump
until the salt is washed from the valve. Do not leave high salt buffers in the valve, as the crystallized
salt may damage the valve. For long-term storage, store the valve in 20% EtOH. Do not expose the
valve to pressures greater than 20 psi.
Care of the Gradient Mixer’s Mixing Chamber
To clean the mixing chamber of residue, such as salt:
1. Disconnect the Gradient Mixer’s cable from the Econo Gradient Pump.
2. Use a 3/8” socket driver or box wrench to carefully remove the top of the mixer by rotating the top
counterclockwise. Refer to Figure 3.
3. The magnetic stir bar may be removed from the mixing chamber by turning the unit upside down
and tapping the unit in the palm of your hand until the stir bar drops out of the chamber.
4. The mixing chamber may now be cleaned as required.
5. The chamber may be flushed by connecting a luer-tipped syringe to the “A” port and slowly passing
fluid through the valve and mixing chamber
To reassemble the unit:
1. Wipe the mixing chamber and threads clean.
2. Insert the stir bar back into the mixing chamber with the flat end of the stir bar toward the bottom of
the chamber. Gently push the stir bar to the bottom of the chamber.
3. Wipe the top and threads clean.
4. Replace the 1.0cm O-ring seal on the top if it is damaged. (The Bio-Rad part number for the O-ring
is 910-0075.)
5. Use a 3/8” socket driver or box wrench to screw the top on the mixer by rotating the top clockwise
until the lip around the top is just flush with the top of the mixing chamber. The seal is made by a
properly seated O-ring, not by the screw threads. To avoid damaging the unit, do not over-tighten
the top.
Technical Assistance
For additional help, contact your local Bio-Rad representative. In the United States, call Technical
Service at 1-800-4BIORAD.