ISE maintenance - Conditioning the Na and K electrodes

Materials required

Biohazard

Time: 45 minutes

Analyzer mode: Manual operation

Wear personal protective equipment.
Use universal precautions.

A new electrode may take a long time to stabilize, so carry out aging of the electrode on the day prior to start of use.

To condition the electrodes

  1. Prepare a 1:4 dilution of pool serum using ISE buffer solution.

  2. Remove the new electrode from its case.

NOTE

The ion electrode contains an inner solution, which can be confirmed by shaking the electrode.  This solution decreases little by little with time. If you do not feel any response in your shaking, measure its weight. If the electrode weighs less than 9 g, do not use it.

  1. Remove the sponge from the bottom of the electrode case and place the electrode to be conditioned back into the case.

  2. Using a dropper or pipette, pour 0.5 mL of pool serum into the flow path of the electrode. Be sure to apply the serum thoroughly.

  3. Add buffer solution to the case, covering the whole electrode with solution. Let the electrode condition overnight.

  4. After aging is complete, take out the electrode, wash it with deionized water, and thoroughly wipe it off.

 warning

To prevent infection from contacting serum directly, wear suitable protective gloves when you remove the electrode from the solution.

NOTE

High-concentrated salt water is used as a preservation solution to maintain electrode performance. When the electrode package is opened, wash the electrode with sufficient water and wipe well before use. Small amounts of salt on the electrode may cause rust on the electrode connector.

NOTE

To store the reference electrode, remove it from the ISE module, rinse it with water then place it into an appropriate container. Cover the reference electrode with ADVIA 2400 ISE reference electrode filling solution. Cover the container and store at 0 to 40 °F (-18 to 4.5 °C). Rinse with water prior to next use.

  1. Replace the electrodes on the instrument with the newly conditioned ones.  

  2. Calibration is performed as part of the electrode replacement.  If the calibration fails, repeat calibration again. If data continues to be unstable after electrode conditioning, perform an electrode wash.