How to perform washes on the NextSeq 500/550

**There are three types of washes on the NextSeq 500/550.

1. Automatic post-run wash:** performed automatically after each run. 2. Quick wash: (20 minutes) required every 14 days the instrument is idle. Laboratory grade water and Tween 20 are supplied by the user.

2. Combine the following volumes to result in a 0.05% Tween 20 wash solution: 20 µl of 100% Tween 20 and 40 ml Laboratory-grade water. Load 40 ml of 0.05% Tween 20 wash solution to the center reservoir of the buffer wash cartridge.

3. Select Perform Wash, and then select Quick Wash.

3. Manual post-run wash: (90 minutes) required if the automatic post-run wash was not performed. Laboratory grade water, Tween 20, and NaOCl (0.12%) are supplied by the user. (Bleach must be lab-grade bleach. Household/commercial bleach cannot be used because the concentration is not controlled.)

1. Combine the following volumes in a microcentrifuge tube to result in 1 ml of 0.12% NaOCl: 24 µl of 5% NaOCl and 976 µl of Laboratory-grade water (976 µl). Invert the tube to mix. Add 1 ml of 0.12% NaOCl to position #28 in the reagent wash cartridge.

2. Combine the following volumes to result in a 0.05% Tween 20 wash solution: 75 µl of 100% Tween 20 and 150 ml of Laboratory-grade water. Load 150 ml of wash solution to the center reservoir of the buffer wash cartridge.

3. Select Perform Wash, and then select Manual Post-Run Wash.

Note: The new NextSeq 550 buffer wash cartridge has a label listing the minimum (150 ml) and maximum allowable volumes. Users can still use the 40 ml volume for quick washes or 120 ml, as there have been no changes to the wash recipes.

For any feedback or questions regarding this article (Illumina Knowledge Article #3076), contact Illumina Technical Support [e-mail].