Perform a Diluted Bleach Tip Wash

This procedure describes a tip wash using a 1:10 bleach dilution on the IAPS with ILASS. If the instrument tips came in contact with DNA, perform the bleach wash at the end of the day.

The tip coating is sensitive to bleach. Perform the bleach wash only as directed and one time per day.

The bleach wash makes sure that the fixed pipetting tips are properly cleaned and decontaminated of residual DNA. The wash also makes sure that the tips are ready for use with the best possible pipetting conditions while also avoiding contaminating carryover. Failure to perform a bleach wash routinely can contribute to inaccurate results.

You can perform a wash at any time. Unlike the system flush, EVOware does not enforce the bleach wash. Tecan tips are sensitive to bleach. Never run the bleach wash more than one time per day to avoid degradation of the tip coating.

Perform a EVOware bleach wash as follows.

1. Make sure that the system liquid carboy contains enough system liquid for the upcoming runs and that the liquid waste container is empty.
2. Launch and sign into the EVOware application using the appropriate user name and password.
3. From the EVOware software home page, select Infinium Maintenance Procedures.
4. Open the instrument front safety door and add 20 ml 1:10 bleach solution (1 part bleach, 9 parts water, containing 0.5–1% sodium hypochlorite final) to a 40 ml quarter reservoir and place it in a reservoir frame.
5. Place the reservoir frame on flat plate nest Carrier 7 (Grid 8), Site 1 (at the back of carrier with the reservoir on the left-most side of the frame).

Make sure that the reservoir frame is placed correctly. For guidance on the correct placement of the reservoir frame, refer to the worktable diagram in the EVOware user interface.

6. Close the front safety door.
7. Navigate to Bleach Wash and select Start.
8. Follow the prompts to execute the run.

If the system flush is overdue (more than two hours after the last flush), the system performs a system flush before performing the bleach wash. During the bleach wash, each tip aspirates 450 µl bleach solution into the tips and system tubing. After a two minute incubation, the instrument discards the bleach and flushes the tips with system liquid to remove any remaining bleach.

9. Open the front safety door and discard the bleach wash.
10. Rinse, dry, and store the labware.

Perform the bleach wash using EVOware as follows.

1. Make sure that the system liquid carboy contains enough system liquid for the upcoming runs and that the liquid waste container is empty.
2. Using the administrator user name and password, log in to the EVOware Standard application.
3. Select the green arrow, and then select Run an existing script.
4. Select the green arrow again to continue.
5. Select the script that starts with EVO_UTILITY_Bleach_Wash.

If multiple scripts have the same name, use the script with the most recent version number.

6. Select the green arrow to continue.
7. Open the front safety door of the instrument.
8. Add 20 ml 1:10 bleach solution (containing 0.5–1% sodium hypochlorite) to a 40 ml quarter reservoir and place in a reservoir frame.
9. Place the reservoir frame on flat plate nest Carrier 7 (Grid 8), Site 1 (at the back of carrier with the reservoir on the left-most side of the frame).

Make sure that the reservoir frame is placed correctly. For guidance on the correct placement of the reservoir frame, refer to the worktable diagram in the EVOware user interface.

10. Close the front safety door and select Run with the green arrow.
The Runtime Controller window opens and shows the path of the newly opened script in the Run script! field.
11. Confirm that the Run full script? checkbox is selected.
12. Select Run to execute the script and follow any additional informational prompts.

The liquid system aspirates 450 µl of the 1:10 bleach dilution into the tips and system tubing. After a two minute incubation, the instrument discards the bleach and flushes the tips extensively with system liquid to remove any remaining bleach.

13. After the bleach wash completes, select New, and then select Cancel to exit the Runtime Controller window.
14. Exit and close the EVOware Standard application.
15. Open the front safety door and discard the bleach wash.
16. Rinse, dry, and store the labware.