Heat fixation procedure, purpose ,factors affecting fixation microbiology

Heat fixation is the second method after the chemical fixation in histology. 

what is heat fixation in microbiology?

The mechanism of heat fixation is, that it denatures the protein. It takes two to three minutes. 

Microwave ovens have overtaken the conventional heating method, due to their controlled environment. 45-55 C is the optimum temperature of it.

Microwave fixation allows the light microscopic technique used in routine histopathology to be performed adequately. Microwave the tissue at 50 C. Post fixation in osmium tetra-oxide gives satisfactory results for electron microscopy.

Heat fixation vs chemical fixation

• In heat fixation, we use heat as a fixative agent for tissue fixation on the other hand, in chemical fixation we use different chemicals like 10%neutral buffered formalin, osmium tetraoxide, Zenker solution other fixatives.

5 Factors affecting the fixation process in histology

The following factors affect the fixation mechanism.

1. Size and thickness of fixing tissue.
2. Fatty and lipomatous tissue fix slowly.
3. Tissue covered by a large amount of mucus, blood fix slow.
4. Slow agitation.
5. Low temperature.

Which factors accelerate the fixation process?

For optimum result and ideal fixation following factor saves our time and accelerates the fixation process.

• The tissue should be 5-micron thickness.
• Agitation increase the fixation.
• 60 centigrade is the optimum temperature of fixation.