title: GSM5907085: AD_2_NL; Homo sapiens; RNA-Seq
library_construction_protocol: Human skin biopsy samples were snap-frozen in liquid nitrogen-cooled isopentane and placed in a –80 °C freezer for long-term storage. To prepare tissues for cryosectioning, fresh-frozen tissue samples were embedded in ice-cold optimal cutting temperature (OCT) compound (Tissue-Tek, Sakura Finetek, USA) and frozen on powdered dry ice. After solidification, the OCT embedded tissue block was used immediately for cryosectioning. Block was equilibrated in a cryostat for 30 min with a cryostat chamber temperature adjusted to –20 °C and specimen stage temperature set to –15 °C. Embedded tissues were cryosectioned at 12 μm thickness and transferred onto a Visium optimization slide or a gene expression slide (10X Genomics, USA). Slides were kept in chilled slide mailers on dry ice and transferred to the –80 °C freezer. Visium Spatial Gene Expression Slide with cryosectioned tissue sections were dried for 1 min at 37 °C, fixed in chilled 100% methanol for 20 min and stained with hematoxylin and eosin for 7 min and 1 min, respectively. Brightfield images for the spatial gene expression slides were captured using an Axio Z1 slide scanner (Zeiss, Germany). Gene expression samples were prepared by permeabilization of tissues for 18 minutes, as optimally determined using the Tissue Optimization Kit. Gene expression libraries were constructed according to the Visium Spatial Gene Expression Reagent Kits User Guide (Rev D, 10X Genomics).