Aim
To perform a test detecting the presence of albumin in the given sample of urine.
Theory
What is albumin?
Albumin is a protein that is produced by the liver. It is a typical constituent of blood that is filtered by the kidney.
What is the significance of albumin?
- It maintains the intravascular oncotic pressure thereby checking the stability of the fluid pressure inside the blood vessels.
- It acts as a carrier proteins for fatty acids, thyroid hormones, steroids in the blood
About Albuminuria
A normally functioning kidney has very less to no traces of albumin in the urine, about 250mg in normal urine in a day. Any damage to the kidney causes an unusual range of albumin, way above the normal level to enter into the urine. This condition is known as albuminuria. If the albumin level is very little and persists to stay abnormal, then the condition is referred to as microalbuminuria.
Causes:
- Can be caused due to the kidney damage from the condition of diabetes
- Albuminuria can also be caused by kidney damage caused by heart failure, high blood pressure, lupus and cirrhosis
Tests that can be carried out to detect the presence of albumin in urine are:
- Heller’s Test – A white ring is caused due to albumin precipitation
- Sulphosalicylic acid Test – Coagulation resulting in white cloudiness in the solution
1. Heller’s Test
Material Required
- Concentrated nitric acid
- Urine sample
- Test tube
- Measuring cylinder
- Dropper
- Test tube holder
Procedure
- From the reagent bottle, add 5ml concentrated nitric acid accurately using a measuring cylinder, pour it into a test tube
- From the sample urine bottle, add some drops of the urine sample with the help of a dropper
- Pour some sample of urine along the inner side of the test tube with the help of a dropper and by inclining the tube.
- The above step is performed so as to form a covering on the nitric acid
- Notice the changes taking place in the test tube.
Observation And Conclusion
The changes taking place in the test tube is observed. At the intersection of the two layers, a white ring appears which indicates that albumin is present in the given sample of urine.
2. Sulphosalicylic Acid Test
Material Required
- 30% Sulphosalicylic acid
- Urine sample
- Measuring cylinder
- Burner
- Test tube
- Test tube holder
- Dropper
Procedure
- From the sample urine bottle, add 2ml sample of the urine accurately using a measuring cylinder, pour it into a test tube
- Add some drops of the sulphosalicylic acid with the help of a dropper into the tube holding the urine sample
- The solution in the tube turns into a white color
- Securely hold the tube with the help of a holder to heat upon the burner gently.
- Make note of the changes observed
Observation And Conclusion
The given sample of urine appears as a cloudy turbid solution or whitish which indicates that albumin is present in the sample.
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