Urinalysis

• 180L/day filtrate  1.8L/day urine
• Sterile
• Contains:
– Water (~ 95%)
– Urea (from amino acids)
– Creatinine (from muscle creatine phosphate)
– Uric acid (From nucleic acids)
– Urobilins (urochrome)
– Electrolytes

Table 26–5

• pH = 6.0 normally
– Can be amore acidic due to respiratory problems, acidosis, uncontrolled diabetes, starvation and high protein diets
– Can be basic due to chronic renal failure, UTI, vegetarian diet
• Ketones in the urine (starvation, diabetes) give it an fruity smell
• Glucose in the urine may give is a sweet smell

• Urea : breakdown of amino acids in the liver and other cells leads to the production of ammonium ion NH
4
+
 urea
+ CO
2
• Uric Acid : breakdown product of nucleic acids
• Creatinine : from muscle metabolism of creatine phosphate

• Color
• Turbidity
• Smell
• Density (specific gravity)
• Sometimes:
– Glucose
– Albumin (plasma protein)
– Ketones
– Hemoglobin
– RBCs
– Bilrubin
– Nitrites
– WBCs
– Casts
Contents
:
• Water
• Chemicals:
– Urea
– Na+, K+
– Phosphate, sulfate ions
– Creatinine
– Uric acid
– Urobilins

Specific Gravity is a measure of urine concentration
Excessively concentrated urine can crystallize over time forming kidney stones

• Get into groups
• In each group, one person can do an unknown pathological “urine” sample; others use your own urine sample
• Collect your sample – starting at midstream is best
• Note characteristics (color, turbidity, odor)
• Test specific gravity with urinometer – rinse and place in bleach when done

• Test pH with pH paper (optional)
• Test for Sulfates, Phosphates & Chlorides - all chemical tests done in the test tubes provided.
• Glucose with the Clinitest tablets.
• Bilibubin with the the Ictotest.
• Multistix test strips for leukocytes, nitrite, urobilinogen, protein, blood, bilirubin, pH, specific gravity, and glucose (note the time differences among them)
• Centrifuge, stain and examine

• Sulfates
– Measure 5ml of urine an put in test tube
– Add a few drops dilute HCl
– Add 2ml of 10% barium chloride
– Precipitates indicate sulfates
• Phosphates
– Place beaker ½ of water on hot plate and heat
– Put 5ml urine in test tube with 3-4 drops nitric acid and 3ml aluminum molybdate
– Mix well with glass rod, then heat in bath
– Yellow precipitate indicate phosphates
• Chlorides
– To 5ml of urine in a test tube add several drops AgNO3
– White precipitate indicated chlorides

• Glucose
– Obtain the Clinitest tablets and color chart for comparison
– Put 5 drops of urine into a test tube
– Rinse dropper and add 5 drops of water to the tube
– Add Clintiest tablet, wait 15 sec, then compare color to chart
• Bilibubin
– Place one drop of urine in the center of the Ictotest mat with the the Ictotest.
– Place Ictitest tablet on top of urine drop
– Add two drops of water directly to the tablet
– Purple = bilirubin

• Use Multistix test strips for leukocytes, nitrite, urobilinogen, protein, blood, bilirubin, pH, specific gravity, ketones, and glucose (note the time differences among them)

• DO THIS FIRST
• Pour portion of sample into tube (10ml)
• Give to me to centrifuge
• When I return it, pour off the supernate
• Take a sample of the pellet (sediment)
• Put one drop on the slide with drop of stain
• Cover slip examine and draw, comparing to figure

• Review Sheet 41
• Drawing of 2-3 interesting things seen in the urine
• Page 625 with results for real urine sample and pathological sample (record # at top of page)
• Due next Thurs