Why is the baseline a flat line at 178 nA?

The Exoid detects current between -178 and 178 nA, if the current is outside of this range, the trace will 'rail' and appear as a flat line, shown below:

To correct this, lower the applied voltage until the trace appears within the range of -178 to 178 nA, or reduce the stretch on the nanopore. 'Railing' may also occur if there is a short-circuit in the system (due to liquid contacting some of the metal). To fix this, remove the upper fluid cell and wipe the metal contacts dry with lint-free tissue, then reassemble the fluid cell. If the current is still too high, fully disassemble, clean and dry the fluid cell.

This can also occur if the user is working at a high baseline (e.g. >140 nA) and the nanopore has ruptured and become larger, as a larger nanopore will have a higher current than a smaller nanopore at the same operating conditions.