Instruction manual

Fluid Operation
General Fluid Operation
Rev. B MultiMode SPM Instruction Manual 129
Note: To minimize the risk of fluid leakage, introduce fluid to the fluid cell under
vacuum using the following technique:
• Attach a piece of silicone tubing to one of the fluid ports using a male Luer fitting.
Place the free end of the tubing into a beaker containing the buffer.
• Attach a piece of silicone tubing to the other fluid port using a male Luer fitting.
• Fill the fluid cell with fluid by withdrawing the plunger on the syringe. This will
draw fluid from the beaker containing the buffer through the fluid cell. Stop
withdrawing the plunger on the syringe when fluid begins to fill the syringe.
• Check for leaks and wick away any spilled liquid with filter paper until AFM
components are dry.
7. Bubbles inside the fluid cell near or on the probe can interfere with the laser beam. Remove
bubbles by performing the following procedure:
a. Observe the fluid cell and probe through the viewing port using an optical microscope.
b. Rapidly pull liquid through the cell with a syringe. If sufficient force is applied, the
bubbles will be carried out of the fluid cell.
Method 2: Without an O-ring
In many cases, it is possible to image a sample under a drop of fluid without use of a closed fluid
cell. This technique is recommended for aqueous buffers, when evaporation is not an issue; (for
example, in short experiments and those involving no use of volatile solvents).
Limit risk of leakage as follows:
• Use a sample support larger than the puck.
• Use the recommended adhesive Loctite 770 to affix a Teflon cover over the steel sample
puck. The Teflon should extend slightly over the edge of the sample puck. Use epoxy to
attach the sample support to the Teflon.
The hydrophobic Teflon helps confine the solution without installing an O-ring (see Figure 8.2d).
CAUTION: Without the O-ring, this method poses a potential spill hazard to
microscope electronics and must always be undertaken with
extreme caution. Limit the volume of liquid in the fluid cell to 30-
50µl when possible.