title: GSM8944111: FCDI_2; Homo sapiens; OTHER
library_construction_protocol: Tissue sections were first quality-checked, and only those meeting the criteria proceeded to further processing. OCT-embedded tissue blocks were cryosectioned at a thickness of 10 μm using a Leica CM1950 cryostat under controlled conditions (-20°C). Sections were fixed with methanol and subjected to hematoxylin and eosin (H&E) staining to visualize tissue architecture, allowing selection of optimal sections. Tissue permeabilization was optimized using the 10x Genomics Visium Spatial Tissue Optimization slides and reagent kits. High-resolution imaging was performed using a Nikon ECLIPSE Ti fluorescence microscope to determine the optimal permeabilization time for tissue sections. Tissue sections were placed within the capture area of the spatial gene expression slide. After H&E staining, tissue morphology was examined under a brightfield microscope, followed by permeabilization to release cellular mRNA. The mRNA or probes hybridized with oligonucleotides containing spatial barcodes on the spots. Reverse transcription was performed within the capture area to generate barcoded cDNA, which was subsequently amplified. The cDNA was fragmented to an appropriate size (200–300 bp) using the 10x Genomics reagent kit. High-quality libraries were obtained through PCR amplification and assessed using an Agilent 2100 Bioanalyzer. The final libraries were sequenced on the Illumina NovaSeq 6000 platform for high-throughput analysis.