6. Enzyme Histochemistry

Question 1

What is Enzyme Histochemistry

Answer 1

Method for localising cellular structures, using spec enzyme activity present in those structures

Question 2

What is done to preserve the enzymes?

Answer 2

Unfixed/mildly fixed tissues

Sectioned on cryostat - effects of heat/organic solvents of enzyme activity

Question 3

Method?

Answer 3

Method: Uses the fact that enzymes react with specific chemical bonds

- Tissue sections are immersed in a solution containing the substrate of the enzyme to be localized
- The enzyme is allowed to act on its substrate
- At this stage/ later, the section is put in contact with a marker compound that reacts with a product of the enzymatic action on the substrate
- Final product from the marker, which must be:
• Insoluble
• Visible by light/electron microscopy by having colour or electron density

• Precipitates over the site that contains enzymes – identifying location
• When looking with microscope, region is covered with coloured/electron dense material

Question 4

What do you see when looking through with a microscope?

Answer 4

• precipitates over site of enzymes - identifies location

- you see region with colour/electron dense material