Download Lab 41 Urinalysis

Lab 41
Urinalysis
Urine
• 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
General Characteristics
of Normal Urine
Table 26–5
Urine – variable components
• 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
Nitrogenous wastes
• Urea: breakdown of amino acids in the
liver and other cells leads to the
production of ammonium ion NH4+ + CO2
 urea
• Uric Acid: breakdown product of nucleic
acids
• Creatinine: from muscle metabolism of
creatine phosphate
Urine characteristics
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Color
Turbidity
Smell
Density (specific
gravity)
Contents:
• Water
• Chemicals:
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Urea
Na+, K+
Phosphate, sulfate ions
Creatinine
Uric acid
Urobilins
• Sometimes:
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Glucose
Albumin (plasma protein)
Ketones
Hemoglobin
RBCs
Bilrubin
Nitrites
WBCs
Casts
Specific Gravity is
a measure of urine
concentration
Excessively
concentrated urine
can crystallize over
time forming kidney
stones
Today
• 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
Today
• 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
Tests for Sulfates, Phosphates,
Chlorides
• Sulfates
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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
Tests: Glucose, Bilirubin
• 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
Multistix
• Use Multistix test strips for leukocytes,
nitrite, urobilinogen, protein, blood,
bilirubin, pH, specific gravity, ketones, and
glucose (note the time differences among
them)
Staining
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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
Turn in
• 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