Labeling possible throughout section 4. Serial sections easy 5. Storage blocks and sections easy 6. Equipment common in EM lab 7. Disadvantages Loss of structure, translocation with permeabalization B. Post-embedding immunolabeling enables more control of morphology 1.
Fixation allows storage.
Embedment media may mask antigens 3. The goal of fixation is to stabilize the cellular constituent in their native positions. Overfixed tissues may respond to epitope retreival methods. Physical fixation may preserve antigen integrity but at the expense of morphology. For many enzymatic techniques frozen specimens may be necessary.