S3309

Spatial transcriptomics arrays include four identical 6.5 mm × 6.5 mm capture areas, and each with 4992 spatial-barcoded spots (10× Genomics). Every spot has a diameter of 55 μm, and surrounding with six spots with a center-to-center distance of 100 μm. Tissues were cryosectioned, cut at 10-μm thickness, and then mounted onto spatial slides. Using the Thermocycler Adaptor with the active surface facing up, sections were incubated for 1 min at 37 °C. The slides were then fixed by methyl alcohol for 30 min at –20 °C, followed by H&E staining (Eosin, Dako CS701, Hematoxylin Dako S3309, bluing buffer CS702) and brightfield imaging with a Leica DMI8 whole-slide scanner at 10× resolution.

The bladder tissues (6.5 mm × 6.5 mm × 6.5 mm) from all participants were snap-frozen with precooled isopentane and then embedded with O.C.T. compound. Cryosections were cut with 10 μm thickness and mounted onto the GEX arrays. Sections were placed on Thermocycler Adaptor with the active surface facing up and incubated 1 min at 37 °C, and then were fixed for 30 min with methyl alcohol in −20 °C followed by staining with H&E (Eosin, Dako CS701, Hematoxylin Dako S3309, bluing buffer CS702).^{54 (link)} The brightfield images were taken via a Leica DMI8 whole-slide scanner at ×10 resolution.