A Urea test is used to determine how well your kidneys are working. It does this by measuring the amount of urea nitrogen in the blood. Urea is a waste product that’s created in the liver when the body breaks down proteins. Normally, the kidneys filter out this waste, and urinating removes it from the body.
![Urea Test Procedure](https://www.labtestsguide.com/wp-content/uploads/2020/01/Urea-Test-3-1024x576.jpg)
Urea levels tend to increase when the kidneys or liver are damaged. Having too much urea nitrogen in the blood can be a sign of kidney or liver problems.
Panel Tests: Urea, Blood Urea Nitrogen, Creatinine, Calcium, Phosphorus, Albumin, Magnesium, Total Protein, Electrolytes
Test Procedure:
Berthelot Method
Test Principle:
Urease hydrolyzes urea to ammonia and Co. The ammonia formed 2 further reacts with a phenolic chromogen and hypochlorite to form a green coloured complex. Intensity of the colour formed is directly proportional to the amount of urea present in the sample.
Kit Components:
- Reagent 1 : Urea Enzyme Reagent
- Reagent 2 : Urea Chromogen Reagent
- Reagent 3 : Urea Standard 40 mg/dl
Reagent Preparation
Bring all the reagents to Room Temperature.
Working reagent – Dissolve the enzyme reagent (Reagent 1) in Deionised water as per volume indicated on the vial.
Reagent 2 – is ready to use
Sample Preparation:
- Serum: No Need any Preparation
- Urine: Dilute urine 1 + 49 with distelled water.
TEST PARAMETERS | |
---|---|
Method | Endpoint, Berthelot method |
Wavelength | 600 nm (600-630 nm) |
Temperature | 37°C |
Sample | Serum, heparin plasma, urine |
Linearity | upto 200 mg/dl |
Sensitivity | The lower limit of detection is 10 mg/dL |
MANUAL TEST PROCEDURE
Bring reagents and samples to room temperature.
Pipette into clean dry test tube labeled as Blank (B), Standard (S) and Test (T):
Addition Sequence | Blank (B) | Std/Cal (S) | Sample (T) |
---|---|---|---|
R1 (Working Reagent) | 1 ml | 1 ml | 1 ml |
Sample | – | 0.01ml (10 µl ) | |
Standard/Calibrator | – | 0.01ml (10 µl ) | – |
Mix well and Incubate at 37°C For 5 min. | |||
R2 ( Chromogen Reagent ) | 1 ml | 1 ml | 1 ml |
Mix well and incubate for 5 minutes at 37°C. Measure the absorbance of Standard (Abs.S) and Test (Abs.T) against reagent blank at 600 nm within 60 minutes. |
CALCULATION (light path 1 cm)
![Urea Calculation](https://www.labtestsguide.com/wp-content/uploads/2020/01/Urea-Calculation.jpg)
NORMAL VALUE :
- Serum/Plasma =10 – 50 mg/dl
- Urine = 15 – 30 gm/24 hrs
Calculation of Urea Nitrogen:
BUN = Urea/2.14 = mg/dl
Normal:
- Serum: 7 to 20 mg/dL
- Urine: 12 to 20 g /24 hours
Related Articles:
Possible References Used