بايو عملي

• Urine


  One of the biological fluids which is responsible for the removal of waste products, toxic substances from the body
• Normal urine excretion


  • The normal quantity of urine passage daily varies widely, it range from 700-2500 mL
• Factors affecting normal urine excretion

  • Fluid intake
  • The weather
  • The time of excretion, normally, more urine is excreted during the day in comparison to night
  • Pathological state of the patient
• Polyuria


  A pathological condition by which an increase in urine output, more than 2500 mL/day
• Causes of polyuria


  • Diabetes mellitus
  • Diabetes insipidus
  • Renal failure
• Oliguria

  A pathological decrease in the urine output, less than 400 mL /day
• Causes of oliguria

  • Dehydration states, because of diarrhea, vomiting, fever, severe hemorrhage
  • Sudden lowering of blood pressure, that is, hypotension
  • Severe heart failure
• Categories of general urine examination

  • Physical examination
  • Biochemical examination
  • Examination of Urinary Deposits
• Physical examination of urine

  • Color
  • Appearance
  • Reaction (pH)
  • Specific gravity
• Normal urine color


  Light yellow due to pigments Urochrome and uroerythrin
• Presence of small quantities of blood in urine

  Urine has a smoky appearance
• Presence of larger quantities of blood in urine

  Urine has a brownish or red color
• Presence of bile pigments in urine

  Urine has a brown color and produces yellow froth when shaken
• Some drugs may also lead to discoloration of urine
• Normal urine is quite transparent when freshly passed, but it may become opalescent due to existence of various substances that forms a suspension, the most important of which are the pus, bacteria, and phosphates
• Normal urine pH


  Slightly acidic, with a pH range between 6 and 7
• Specific gravity of urine

  Can be measured using a hydrometer, the normal range is 1.010─1.025
• Conditions where urine specific gravity increases

  • Dehydration
  • Heavy proteinuria
  • Glucosuria
• Diabetes insipidus

  Urine specific gravity decreases
• Normal constituents of urine

  • Chlorides, phosphates, and the sulfates of sodium, potassium, calcium, and magnesium
  • Uric acid, creatinine and ammonium salts
• Uric acid


  Derived partly from the metabolism and breakdown of food proteins and tissue proteins
• Follin test for uric acid

  2 mL of urine + few drops of (Follin phosphotungstic acid reagent) + a small amount of anhydrous Na2CO3 -> mix -> a deep blue color is produced
• Jaffe's test for creatinine

  1 mL of sat. picric acid soln. + 0.5 mL of 10% NaOH + 3 mL of urine -> mix -> A deep reddish-orange color, indicates the formation of creatinine-picrate complex
• Ammonium salts


  Normally an average of 4% solids are dissolved in urine, of which 2% is urea, 1% is sodium chloride, and the other organic and inorganic constituents make up the remaining 1% of solids
• Ammonia test

  2 mL of urine -> boil for 3 min -> NH3 -> moist red litmus paper -> blue color
• Abnormal constituents of urine

  Glucose and other reducing substances, Protein, Ketone bodies, Bilirubin and Urobilinogen
• Glucose and other reducing substances

  Act to reduce benedict reagent, in addition to glucose, other substances such as galactose, fructose, lactose, maltose, ascorbic acid (vitamin C), acetylsalicylic acid (aspirin), homogentisic acid behave by the same manner
• Benedict's test


  Benedict's reagent + 0.5 mL of urine -> boil for 5 min, then cool -> a reddish-orange color
• Protein in urine


  Before doing the test, the urine should be clear, two common tests are sulphosalicylic acid test and boiling test
• Boiling test


  Take 5 mL of urine in a test tube. 2. Incline the tube on a flame, boil. 3. Add few drops of acetic acid.
• Bence-Jones protein


  An abnormal protein that is excreted particularly in urine of patient with multiple myeloma, it considered as a sign of tumors or a tumor-makers
• Fouchet's test for bilirubin

  Saturate a filter paper with few mL of BaCl2 solution + 5 mL of urine. 2. Spread the filter paper on another dry paper + 1 to 2 drop of (25% trichloroacetic acid) -> greenish-blue color appear
• Hay's test for bilirubin


  Take small amount of urine in a test tube and sprinkle a finely powdered dry sulfur over the surface of urine, if bile salts are present, sulfur will sink, if bile salts are absent, sulfur will remain floating
• Ehrlich's test for urobilinogen

  5 mL fresh urine +0.5 mL Ehrlich's reagent -> Allow to stand for 3-5 minutes -> note any color produced (almost pink color or red)
• Clinical significance of urobilinogen

  Urobilinogen is raised in hemolytic jaundice, liver cirrhosis
• Reagents employed for urine examination

  • Sulphosalicylic acid (20%)
  • Benedict solution
  • Sulfur powder
  • Barium chloride solution
  • Fouchet's reagent
  • Ehrlich's aldehyde reagent
  • 6 mol/L HCl