Step 1: Fixation (two containers)

Tissue should be fixed with formalin to prevent the activity of enzymes to destroy tissue before starting the passage stage

Fixation is an action that causes the sudden or simultaneous killing of cells in a tissue.So that as much as possible the shape and composition of the cells Do not change over time. Biopsies should remain in 10% formalin for at least 24 hours. The properties of formalin are very important for full penetration of formalin. The tissue should be completely drown in the formalin in an open manner.


The commercial formaldehyde solution, 73% degree in water, is called formalin, and we consider it to be pure formalin. For diluting 9 parts of water are added to 1 part of formalin to achieve 10% Formalin for fixing the sample.


If the tissue parts are too and because of lack of complete fixation, They can be incorporated into the process exceptionally, because alcohol has some fixing properties


Large tissues should be cut into pieces and some cotton should placed between them so that formalin penetrates into the tissue via the cotton


.Uterine tissue should remain in 10% formalin for 7 to 2 days


Figure 1 :Fixation by formaldehyde, which stabilizes proteins




Figure 2 : inappropriate Fixation Has led to wrinkling of tissue


Figure 3 – Did Sabz Tissue processor for passage and tissue preparation

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