If you need to shut down your Aurora or Northern lights cytometer for an extended period of time (e.g. more than 1 week), follow the steps below to properly clean and decontaminate the fluidic lines to ensure the system will operate smoothly when it is time to turn it back on.

Materials

• Approximately 1L of 10% household bleach solution (1 part Clorox household bleach diluted in 9 parts DI water)
• Approximately 2L of DI water - this is key to prevent bacterial growth in the lines while the system is off
• Two 5mL polystyrene tubes containing 3mL 10% bleach
• Four 5mL polystyrene tubes containing 3mL DI water

Steps

1. Power on the instrument.
2. Open SpectroFlo, log in and wait for the software to connect.
3. Optional: Perform an overnight Contrad soak to thoroughly clean the flow cell by running Fluidics Shutdown with 2 modifications:
   1. In Step 4, instead of running DI water, load another tube containing 3mL 25-50% Contrad.
   2. Once Fluidics Shutdown is completed, remove the Contrad tube from the cytometer and load a tube containing approximately 1mL DI water.
   3. Power off the system and leave it overnight.
   4. The next morning, power on the instrument and connect to SpectroFlo.
4. Perform a Long Clean following the steps in the wizard. If you are using a saline-based sheath fluid, use DI water at step 4 (minute 4.12) of the Long Clean. Long Clean Video Tutorial
5. When the Long Clean has completed, run Fluidics Shutdown. Instead of running the four tubes prompted by the software wizard (10% bleach, DI, 30% contrad, DI), ONLY run four DI water tubes.
6. When the Fluidics Shutdown is complete, power off the instrument and leave a tube containing approximately 1mL DI water on the sample injection port (SIP). This will keep the sample line wetted and prevent it from drying out.

Resuming Operation

1. Power on the instrument.
2. Open SpectroFlo, log in and wait for the software to connect.
3. Optional: If you'd like to replace the DI water in the system with a different sheath, run a Long Clean using 10% bleach, and then your desired sheath.
4. Open a Default Experiment and set flow rate to Medium.
5. Load a tube containing approximately 2mL of high quality, filtered DI water and click start.
6. After 30 minutes, click Stop.
7. Run QC to ensure the cytometer is functioning properly.

If the Long Term Instrument Storage procedure above was not performed prior to an extended period of inactivity (e.g. more than one week), please do the following:

1. Empty and rinse out the sheath tank and replace with high quality, filtered DI water.
2. Power on the instrument.
3. Open SpectroFlo, log in and wait for the software to connect.
4. Open a Default Experiment and set flow rate to Medium.
5. Load a tube containing approximately 2mL of high quality, freshly prepared filtered DI water and click Start.
6. After 30 minutes, click Stop.
7. Run QC to ensure the cytometer is functioning properly.
8. If there are any alerts in QC, perform a Long Clean with 10% Bleach followed by sheath or high quality, filtered DI water.
9. Run QC to ensure the cytometer is functioning properly.
10. If there are any alerts in QC, perform a Fluidics Shutdown using 50% Contrad for all four steps. Allow flow cell to soak in Contrad overnight.
11. Repeat steps 2 through 6.
12. Run QC.
13. If there are any remaining issues, call your primary Field Service Engineer or Technical Support at 1-877-92-CYTEK.