Qualitative Test for Urinary Protein

PROTEIN IN URINE(Qualitative Test for Urinary Protein)

PROTEIN IN URINE(Qualitative Test for Urinary Protein)

PROTEIN IN URINE

-Normal urine contains only traces of proteins. When protein is found in urine, the condition is known as proteinuria. 
These proteins may be derived from plasma albumin, plasma globulin, hemoglobin, and other related products of red cells. 

Qualitative Test for Urinary Protein

Method: heat and acetic acid test (Boiling and acetic acid test)

• Principle of heat and acetic acid test (Boiling and acetic acid test)
• Method of heat and acetic acid test (Boiling and acetic acid test)
• Reading of results of Boiling and acetic acid test(heat and acetic acid test)

• Results of Qualitative Test

Method: Sulphosalicylic acid test for Qualitative Test for Urinary Protein

• Principle of Sulphosalicylic acid test
• Reading of results in Sulphosalicylic acid test

PROTEINS-Normal urine contains only traces of proteins. When protein is found in urine, the condition is known as proteinuria.

• These proteins may be derived from plasma albumin, plasma globulin, hemoglobin, and other related products of red cells.

• If urine is contaminated with semen, vaginal secretion, pus or mucus, protein may be found.

• It is therefore essential to collect a mid-stream specimen of urine or a catheterized specimen if necessary. 
• Urine may also contain an abnormal protein like Bence-Jones protein.

Qualitative Test for Urinary Protein

Purpose:- Qualitative Test for Urinary Protein

Name of method:- heat and acetic acid test (Boiling and acetic acid test)

Principle of heat and acetic acid test (Boiling and acetic acid test)

- Proteins are coagulated by heat in acidic urine and do not dissolve on acidification. Whereas, phosphates and carbonates which are also precipitated by heat, dissolve in acid. 

Procedure of  heat and acetic acid test (Boiling and acetic acid test)

• If urine is not clear, filter or centrifuge; and if alkaline, make slightly acid with 2-3 drops of 5% acetic acid. 
• Fill a test tube about 2/3 full with clear urine. 
• Hold the test tube at an angle away from you, and heat the upper portion of the urine until it just starts boiling.
• Turbidity or cloudiness will arise in the presence of protein, phosphates and carbonates. 
• Add a few drops of 5% acetic acid and boil again. Persistence or development of turbidity indicates proteinuria. 
• Turbidity will disappear if it is due to the phosphates or carbonates.

Note:- Occasionally the precipitate may develop only after the addition of acetic acid and reboiling. therefore this must be done even if no precipitate appears after the first boiling. Avoid the addition of excess acid as it keeps the protein in solution, thus preventing its coagulation. If the precipitate disappears on further heating and reappears on cooling, it is likely to be due to Bence-Jones protein in heat and acetic method.

Reading of results:- As this heat and acetic acid test method gives only qualitative estimates of the protein present,

Results Are Reported in heat and acetic acid test method As Follows:-

• - No cloudiness
• +/- Trace, cloudiness barely visible
• + Definite cloudiness with no flocculation and no granularity.
• ++ Granular cloudiness but no flocculation
• +++ Dense, opaque cloudiness,clearFlocculation
• ++++ Very thick precipitation, almost a solid.

Note - Compare the turbidity with clear, unheated urine in another test tube.

2. Name of a method - Sulphosalicylic acid test

Principle of sulfosalic acid  method

:- Sulphosalicylic acid, being an anionic precipitant, neutralizes the protein cation, thus resulting in the precipitation of proteins in sulfosalic acid method.

The procedure of sulfosalic acid  method

• To 1 ml of clear urine, add 3 drops of 25 % sulphosalicylic acid. A precipitate is formed
• the protein is present. :-False positive results may be obtained after the use of certain radio-opaque substances for pyelograms

• if urine contains a high concentration of penicillin.

Reading of in of sulfosalic acid  method results 

:- Results are recorded in the same way as for the heat and acetic method

Interpretation of proteinuria Minimal proteinuria (< 500 mg/24 hours) .	Moderate proteinuria (500 mg to 3.0 g/24 hours)	Proteinuria (> 3.0 g/24 hours)
Urinary tract infections Renal tubular Dysfunction Hypertension Haemoglobinuria Fever or severe emotional stress in otherwise healthy individuals. After exercise or in highly concentrated urine samples.	Chronic glomerulonephritis Multiple myeloma Pyelonephritis Pre-eclampsia Congestive cardiac failure Marked	Acute glomerulonephritis Chronic glomerulonephritis (severe) Nephrotic syndrome

   

A TEST FOR BENCE JONES PROTEIN