Question: What is the Visium Spatial Tissue Optimization Kit (TO) used for?
Answer: The TO kit is used the first time a customer wants to run a NEW tissue type in their lab. One Visium Spatial TO kit can be used to optimize up to 4 tissue samples (4 slides per kit). Each slide has 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.
If planning to process the same tissue type and section thickness across multiple Visium Spatial Gene Expression experiments, only one Tissue Optimization experiment is needed. If tissue section thickness and/or tissue block preparation methods are changed, it is recommended to repeat the Tissue Optimization experiment as the optimal permeabilization time found previously may no longer be ideal.