TISSUE FIXATION
- Tissue fixation
- aim and objectives of fixation
- prevent autolysis and putrefaction of sample
- cause
- coagulation of tissue
- to prevent loss of diffusible substances
- stabilization of proteins
- to fortify or increase strength of tissue specimen
- to make favorable condition for stains
- tissue fixatives or chemical fixatives
- Crosslinking fixatives – aldehydes
- formaldehyde or formalin
- glutaraldehyde
- Precipitating (denaturing ) fixatives – alcohols
- Ethyl Alcohol
- methanol ( sometimes)
- oxidising agents
- for histology
- potassium dichromate
- potassium permanganate
- chromic acid
- for electron microscopy
- osmium tetroxide
- mercurials
- use
- increases staining brightness
- but slow permeability
- types
- mercuric chloride
- zenker's fixative
- Picrates
- bouins fluid
- Karnovsky fixative
Discussion