Which is better to use in terms of looking for the rigid cellular structure SEM or TEM?
In general, if you need to look at a relatively large area and only need surface details, SEM is ideal. If you need internal details of small samples at near-atomic resolution, TEM will be necessary.
Remember, SEM is surface only, TEM is "transmitted" through the sample so internal structure/organells are apparent. May require U.A. and Led staining. Also a secondary fixation using buffered OsO4 or RuO4 also helps with staining, in addition to lipid preservations.