What causes bubbles in the lower fluid cell?

Bubbles in the lower fluid cell can come from a number of sources:

1. If the lower fluid cell does not have sufficient liquid in it, an air pocket may become trapped in the gap between the fluid and the nanopore.
2. Incorrect pipetting technique may introduce air bubbles into the lower fluid cell.
3. Depending on the environmental conditions, evaporation of fluid from the lower fluid cell may cause an air pocket. This usually only happens after a few hours of operation.
4. Air is trapped in the porous electrode paste (in the lower fluid cell) and can come out when fluid is loaded. Pre-wetting the lower fluid cell with electrolyte containing surfactant helps to alleviate bubble formation in the bottom well during the course of a measurement.