Bedside Urine Test
Protocols
Heat coagulation test:
- Reagent – 3%% of Acetic acid
📒Priciple – proteins are coagulated on heating
Procedure –
- Fill 3/4th of the test tube with urine
- Heat upper part of tube with urine
- Coagulum can be formed due to proteins, phosphates or urates
Add 3 to 4 drops of 3% Acetic acid.
If the coagulum persists, then it is due to proteins and if it disappears it is due to phosphates ( Excess of Acetic acid may dissolve traces of proteins giving false negative reaction)
- Add 2 drops of nitric acid to detect the presence of mucin. If the coagulum is due to mucin it disappears on adding nitric acid.
What are the advantages and disadvantages of the heat coagulation test
- Advantage – cheap test which does not require technical expertise
- Disadvantage – specific type of proteinuria cannot be judged
Why should the test tube be heated in upper part?
- Urine in lower part act as control and is used to compare the haziness developed in the upper part with rest of urine
How do we interpret the heat coagulation test
- No cloudiness – absence of proteins
- Haziness – traces of proteins present (upto 10mg/dL)
- Cloudiness (1+) – 10 – 50 mg/dL
- Moderate cloudiness (granular) (2+) – 50 – 200 mg/dL
- Marked cloudiness (Flocculations) (3+) – 200 – 500mg/dL
- Thick cloudy precipitate (4+) – more than 500ng/dL