postnatal Day 4 in mouse heart rep5
The stereo-seq libraries were prepared using Stereo-seq52. Briefly, Longitudinally section the OCT-embedded heart into 10 mm thick slices using a Leica CM1950 cryostat. These slices were then adhered to the Stereo-seq chip. The chip with the tissue sections was incubated at 37C for 3 minutes. Subsequently, the tissue was fixed in methanol at -20C for 30 minutes. Next, the tissue sections attached to the chip were permeabilized, and the released RNA was subsequently captured by the DNA nanoballs (DNB) on the chip. Then, the captured RNA was in situ reverse transcribed into cDNA. After tissue digestion and Exonuclease, I treatment, the cDNA was amplified. For library construction, 20 nanograms of cDNA were used for fragmentation and amplification.