Histology
Histology is the study of tissues. It contributes to an exploration of the pathological processes and their effects.
There are two major categories of tissue sampling:
- Biopsies : removal of very small tissue samples
- Surgical specimens:
- Removal of tissue of up to a few millimetres in size
- Partial or complete organ resection (surgical specimens).
Various devices optimise the obtaining of biopsy or surgical specimen samples for analysis.
The technical chain consists of a number of stages.
Macroscopy
Macroscopy is the examination with the naked eye followed by a description, digital photos and the standardised sampling of surgical specimens.
Fixation
Fixation is a critical stage that makes it possible to prevent tissue autolysis and thereby conserve tissue in a state that is as close as possible to the “in vivo” state.
Inclusion
Inclusion is the stage that aims to replace a tissue’s water content with paraffin.
Coating
This activity concerns both surgical specimens and biopsies and involves preparing paraffin blocks.
Sectioning and staining
With the aid of a microtome, qualified technicians cut the paraffin blocks into sections of 5µ thickness. These sections are then placed on a glass slide before being dried and stained with a view to analysis under the microscope.