Biochemistry Practical 1: Urine Analysis of Normal and Abnormal Constituents
1. Biochemistry Practical 1
(Urine Analysis - Normal & Abnormal urine constituents)
Copied & Formatted From Handout of Dr. Atif & Prof. Farouk By :
Osama Al-Zahrani
@OSAMA_Z96
2. Normal constituents of urine
âą Normal constituent of urine :
1-2 liter
âą Normal volume of urine output per day :
1-2 liters of urine (1.0 - 1.8 liters)
âą Normal color of urine :
Normal urine color ranges from pale yellow to deep amber
âą Normal specific gravity of urine :
1.001 - 1.0301
âą PH of normal urine :
4.5 to 8.0 (average is 6.0, slightly acidic)
3. Normal constituents of urine
âą Chief action of urine :
Excreted waste substance
âą Normal ca++ Excreted in urine :
1- Males: 25-300 mg/24-hour specimen
2- Females: 20-275 mg/24-hour specimen
âą Ammonia Excreted per day :
1- (lower) : 10 ”mol/L -20
2- (Higher) : Up to 35-65 ”mol/L accordant food intake
âą Non-protein nitrogen (NPN) substance present in urine :
1- Consists of all nitrogen constituents of the blood except protein.
2- They are the end products of nitrogen metabolism and may be excreted in the urine.
4. Normal constituents of urine
âą Normal urea level in blood per day :
7 to 20 mg/dL (2.5 to 7.1 mmol/L)
âą Normal urea level in urine per 24 hours :
10-35mg/dl
âą Uric acid :
1- Uric acid is a waste product normally present in the blood as a result of the breakdown of purines.
2- Excessive amounts of uric acid can cause crystals to form in the joints and cause gout.
âą Uric acid Excreted in urine per day :
Little 1 g per day
5. Normal constituents of urine
âą Creatinine :
1- A nitrogenous compound formed as the end product of creatine metabolism.
2- It is formed in the muscle in relatively small amounts, passes into the blood and is excreted in the urine.
3- A laboratory test for the creatinine level in the blood may be used as a measurement of kidney function In the body,
âą Creatinine synthesis :
1- Creatine is synthesized from the amino acids glycine, arginine, and methionine, primarily in the liver, kidneys, and
pancreas, and it is transported from there to all the cells in the body via the bloodstream.
2- Since creatine is involved in all processes that require energy, muscle, brain and nerve cells receive correspondingly
larger amounts.
Creatinine synthesis
6. Abnormal constituents of urine
âą Proteinuria :
1- Urine of healthy individual contains no protein or only traces amounts.
2- The protein can pass through kidney tubule to urine in case the damage of kidney tubule.
âą Microalbuminuria :
1- Detection of nephropathy and diagnosis of DM complication.
2- Associated with face or feet abnormal edema, due to disturbance of fluid balance in body due to protein loss.
3- Quantitative for 24-h urine:
- Male:1-4 mg/dl,
- Female: 3-10 mg/dl,
- Child: 1-10mg/dl
âą Glycosuria :
1- Renal threshold of glucose : is around 160 mg/100 ml.
2- In DM, characterized by:
- Hyperglycemia.
- Usually associated with polyuria (increased volume of urine).
- Urine may be light in color.
7. Abnormal constituents of urine
Hematuria :
1- Positive result due to :
- Normally : No pathological cause.
- Abnormally : Stones or tumors.
2- Need other confirmatory test.
Hemoglobinuria :
1- Presence of hemoglobin in urine
due to rupturing of RBCs.
2- Occur in malaria, typhoid, yellow
fever, hemolytic jaundice and other
diseases.
Ketonuria :
1- Common in uncontrolled DM.
2- Ketonurea present in:
- Disease (DM)
- Starvation
- Vomiting for long time
3- Values :
- Negative test result is normal.
- Small: < 20 mg/dl
- Moderate: 30-40 mg/dl
- large > 80 mg/dl
8. Abnormal constituents of urine
âą Bilirubin (Bile) :
1- Result from hemoglobin breakdown.
2- Elevated in hepatitis and jaundice.
3- Ehrlich reaction, in which diethylaminobenzaldehyde reacts with urobilinogen in acid medium to produce a pink color.
âą Nitrite :
1- Normal urine doesnât contain nitrate but not contain nitrites.
2- In the presence of bacteria, the normally present nitrate in the urine is reduced to nitrite.
3- The test is used for screening for bacteria, positive test indicates presence of more than 10 organisms/ml.
âą Urine leucocytes:
1- This test detects any microbial infection in the body.
2- Positive result = more than 5 leucocytes/hpf. (high power field).
3- If urine stand long time leucocytes lysis and more intense reaction occur.
4- False positives : occurs with vaginal contamination, presence of glucose, albumin, ascorbic acid.
5- Large amounts of oxalic acid can inhibit the reaction.