Gelatin Pretreatment Enables Cryosectioning of Brittle Tissues for Spatial Transcriptomics

We developed GSP-Cryo (Gelatin Solution Pretreatment Cryosectioning), a broadly applicable sample-preparation strategy that enhances tissue mechanical stability through gelatin perfusion or immersion before freezing, while maintaining compatibility with downstream molecular assays. Using A. coerulea, the most technically challenging specimen in this study, we further validated workflow performance across full developmental stages and optimized solution immersion parameters for RNA preservation through comprehensive RNA quality assessments. GSP-Cryo-prepared sections were subsequently used for gradient permeabilization testing and complete Stereo-seq library construction and sequencing, resulting in high-resolution spatial transcriptomic data.