When and how should I clean the lower fluid cell?

Excess fluid can sometimes get in the lower fluid cell between the metal and plastic material. This can be caused by excessive clicking of the fluid cell cap or excessive washing of the lower fluid cell. Presence of stray fluid in the lower fluid cell can cause a temporary short circuit and if not treated quickly, rusting of the metal parts. 


The system could have a short circuit if the baseline current goes to a negative value (nA) such as the example below:

When this happens, the lower fluid cell should be taken out and thoroughly cleaned. Take extra care to not drop or knock the fluid cell as the arms of it can bend and break off.


Cleaning of fluid cell

Remove the fluid cell from the instrument.
  1. Hold the lower fluid cell at the position shown. 
  2. Gently pull the lower fluid cell up for until it disconnects with the qNano body. 
  3. Unscrew the SMA cable. 
  4. Check the inside of the instrument (where the lower fluid cell fits in place) for any signs of fluid or rust.
                Using an Allan key, remove the larger button head screws from bottom of the lower fluid cell.

    Separate the plastic and metal components.


    You may press lightly on the SMA connector. The fluid cell may/may not be spring loaded.  

    Take note the position of the spring!

    The spring will need to be reassembled the same way it's assembled.


    Rinse the top area of the components with deionised water and thoroughly dry the parts with compressed nitrogen gas (or a lint-free tissue). 

    Do NOT immerse the SMA connector


    Reassemble lower fluid cell in the order indicated on diagram.

    • Tighten the screws and ensure that the upper fluid cell still fits into the bayonet groove with slight interference. Do not over-tighten the screws. Over tightening takes out any spring action and would compromise the connection between upper and lower fluid cells.



    Check that there is a slight gap between the plastic and metal parts i.e. there should still be some movement on the spring.


    If the screws are too tight there will be:

    • Loss of (metal) contact between the upper and lower fluid cell.
    • Expansion of the plastic material of the lower fluid cell. 

    If the screws are too loose, the upper fluid cell will not easily fit into the bayonet groove.


    Check that the fluid cells are behaving as expected by establishing a baseline current with a nanopore (any size).