1. Maintaining the similarity of cell morphology and structure: Pre-fixation can maintain the similarity of cell morphology and structure, and prevent cell dissolution and destruction or tissue corruption caused by bacterial reproduction during culture.
2. Keep the special components in the cell similar to the survival state: Pre-fixation can keep the special components in the cell similar to the survival state, that is, it can retain various components and pathological metabolites in the cell.
3. It is convenient to distinguish different tissue components: pre-fixation can produce different refractive index and different affinity for dyes, which is beneficial to the preparation of slices.