I prepared alginate-tannic acid based hydrogel samples I need to check cell adhesion on hydrogel with DAPI staining and SEM techniques. For SEM observation I need freeze-drying after fixation and also I need cross-sectional area observation I know that, and also for DAPI staining after cell seeding, incubation and fixation I need to take cross sectional area of hydrogel before fluorescence microscope observation? Firstly ı seeded 100.000 fibroblast cell/sample in 10 ul media directly on hydrogel, after 1 and half hour adhesion time I completed media to 200 ul, I applied 2 hour 2.5% gluteraldehyde incubation, 3x PBS washing and 20 ul DAPI- 5min incubation, this is my procedure. Pls help m,. thanks.