
occult blood in urine
The chemical method detects free hemoglobin and myoglobin.
occult blood in urine
Principle of occult blood in urine:-
The peroxidase activity of hemoglobin in urine decomposes hydrogen peroxide and oxidized benzidin to form a green-blue color complex.
Requirement: –
- Testtube
- Graduated pipette
- Pasture pipette
- Benzidine powder
- Glacial acetic acid.
- Hydrogen peroxidase
- Pipette
- Tips
Procedure: –
- Place Pinch of benzidine powder in a test tube.
- Add 2 to 3 drops of glacial Acetic Acid.
- Mix well properly.
- Add about 2 ml of hydrogen peroxide to the solution and mix well.
- After mixed add 1 ml supernatant to a test tube level T.
Observation:-
- If no change in color then occult blood is absent.
- The color is changed to Green or blue then occult blood is present.

Color. Report
Green. +
Greenish Blue. ++
Blue. +++
Dark blue. ++++
Clinical significance: –
Haematuria
Renal disease
Bleeding disorders such as Leukemia
Thrombocytopenia
Coagulation factor sufficiency
Hemolytic anemia
Myocardial infarction
Trauma
The chemical method detects free hemoglobin and myoglobin.
Principle:-
The peroxidase activity of hemoglobin in urine decomposes hydrogen peroxide and oxidized benzidin to form a green-blue color complex.
Requirement: –
- Testtube
- Graduated pipette
- Pasture pipette
- Benzidine powder
- Glacial acetic acid.
- Hydrogen peroxidase
- Pipette
- Tips
Procedure: –
- Place Pinch of benzidine powder in a test tube.
- Add 2 to 3 drops of glacial Acetic Acid.
- Mix well properly.
- Add about 2 ml of hydrogen peroxide to the solution and mix well.
- After mixed add 1 ml supernatant to a test tube level T.
Observation:-
- If no change in color then occult blood is absent.
- The color is changed to Green or blue then occult blood is present.

Color. Report
Green. +
Greenish Blue. ++
Blue. +++
Dark blue. ++++
Clinical significance: –
Haematuria
Renal disease
Bleeding disorders such as Leukemia
Thrombocytopenia
Coagulation factor sufficiency
Hemolytic anemia
Myocardial infarction
Trauma



