Question: What is the purpose of the Visium Spatial Tissue Optimization Kit (TO)?
Answer: The purpose of the TO kit is to determine the optimal tissue permeabilization time for each new tissue type, to confirm tissue compatibility, gain familiarity with the Visium workflow. One Visium Spatial TO kit can be used to optimize up to 4 tissue samples (4 slides per kit). Each TO slide contains 8 capture areas to test 6 different permeabilization times, a negative permeabilization control, and a positive cDNA synthesis control. Please refer to the Visium Spatial Tissue Optimization User Guide for more details and recommended slide layout. The permeabilization time that generates the brightest fluorescent cDNA footprint with the least amount of diffusion is the condition that should be used for the Gene Expression experiment.
For additional details regarding what classifies a tissue type as new, the following article is available: When should I perform a Tissue Optimization (TO) experiment?