The spatial RNA integrity number assay for in situ evaluation of transcriptome quality
Linda Kvastad, Konstantin Carlberg, Ludvig Larsson, Eva Gracia Villacampa, Alexander Stuckey, Linnea Stenbeck, Annelie Mollbrink, Margherita Zamboni, Jens P. Magnusson, Elisa Basmaci, Alia Shamikh, Gabriela Prochazka, Anna-Lena Schaupp, Åke Borg, Lars Fugger, Monica Nistér, Joakim Lundeberg
Abstract
The RNA integrity number (RIN) is a frequently used quality metric to assess the completeness of rRNA, as a proxy for the corresponding mRNA in a tissue. Current methods operate at bulk resolution and provide a single average estimate for the whole sample. Spatial transcriptomics technologies have emerged and shown their value by placing gene expression into a tissue context, resulting in transcriptional information from all tissue regions. Thus, the ability to estimate RNA quality in situ has become of utmost importance to overcome the limitation with a bulk rRNA measurement. Here we show a new tool, the spatial RNA integrity number (sRIN) assay, to assess the rRNA completeness in a tissue wide manner at cellular resolution. We demonstrate the use of sRIN to identify spatial variation in tissue quality prior to more comprehensive spatial transcriptomics workflows.