Tissue preparation for microscopic examination

Tissue preparation for microscopic examination 

Main steps 

1.Fixation 

2.Gross examination 

3.Processing 

4.Embedding 

5.Section cutting 

6.Staining 

7.Slide mounting 

Fixation 

It is a chemical process to preserve biological tissues from decay through autolysis. 

fixatives are used for the fixation process. A fixative is a chemical substances prepare in solution which will prevent putrefication and autolysis of the tissues after being removed from the body. 

most widely used fixative - 10% formalin.

Gross Examination 

Describe the specimen through the naked eye and place the required portion in a correct size in a plastic cassette.  

for the purpose of gross examination there is a special place in histology lab is called cut up area.

Processing 

Getting fixed tissue into paraffin wax is called processing  .

there are 3 steps in tissue processing - dehydration, clearing, impregnation  

Embedding 

Process in which the tissues or the specimens are enclosed in a mass of the embedding medium.

Section cutting 

The tissue is cut in about 3-5 mm thick piece processed and 5 microns thick sections are cut on a microtome. 

Staining 

Various stains used routinely in histopathology laboratory for staining. 

Slide mounting 

Permanently mount the sections under the coverslip.