Question: How can Xenium slides be stored prior to a Xenium Analyzer run?
Answer: Xenium slides can be stored short term (up to 1 week) or long term (up to 2 months)* after performing nuclei staining as indicated in the following protocols:
- Xenium In Situ Gene Expression User Guide (CG000582)
- Xenium In Situ Gene Expression with Cell Segmentation Staining User Guide (CG000749)
- Xenium Prime In Situ Gene Expression with optional Cell Segmentation Staining User Guide (CG000760)*
*Testing is in progress for long-term storage of Xenium Prime slides.
Short-term Storage (up to 1 week)
- Store covered slides in 1,000 μl PBS-T at 4°C in the dark
- Ensure that the slide is stored in microbe-free and nuclease-free conditions, with a Xenium Cassette Lid or slide seal applied to prevent evaporation
- If storage beyond 1 week is needed, we recommend transferring the slides to long-term storage
Long-term Storage (1 week - 2 months)
- Prepare cryoprotectant: 30% glycerol solution in PBS (RNase- and nuclease-free)
- Remove all PBS-T from the cassette well
- Add 1,000 μl 70% ethanol and incubate for 2 min at room temperature
- Add 1,000 μl 100% ethanol and incubate for 2 min at room temperature (1st incubation)
- Add 1,000 μl 100% ethanol and incubate for 2 min at room temperature (2nd incubation)
- Remove slide from cassette and place in a slide mailer containing sufficient cryoprotectant to fully submerge the slide. Do not discard slide cassette.
- Store slides in cryoprotectant at -20°C for up to 2 months
- Clean slide cassettes and store until needed
- Rinse under running Milli-Q water
- Spray with 70% isopropanol
- Repeat Milli-Q water and 70% isopropanol wash
- Rinse under running Milli-Q water
- Air dry
Using Slides Stored at -20°C
- Equilibrate slide mailer to room temperature
- Remove glycerol and rinse slide mailer 3x with PBS-T (10 ml or volume sufficient to submerge slides)
- Remove slide from mailer and assemble into stored slide cassette
- Add 1,000 μl PBS-T to the cassette well
Slides can be stored after Xenium Analyzer run (or in the event of a run failure) in a similar manner. Please reach out to support@10xgenomics.com for more information.
If post-Xenium run outputs are desired (e.g. CytAssist or IF), proceed immediately with IF or CytAssist for optimal assay performance (documentation here). Only perform short term storage in PBS-T and proceed to post-run application within 3 days.
Products: Xenium In Situ Gene Expression, Xenium Prime In Situ Gene Expression, Xenium Analyzer