Routine Urine Analysis
Dr.Ather Farooq
MBBS, Mphil Hematology
Urine:
• Is an ultrafiltrate of plasma from which glucose, amino acids,
water and other substances essential to body metabolism have been
reabsorbed.
• Urine carries waste products and excess water out of the body.
Urine consists of:
(96%)
water
(4%)
dissolved solids:
(2%)
Urea: (half)
(2%)
Other compounds
Inorganic:
Cl-, Na, K.
trace amounts of:
sulfate, HCO3 etc.)
Organic:
creatinine
uric acid
Collection of urine specimens
• Containers for collection of urine
should be wide mouthed, clean
and dry.
• Analysed within 2 hours of
collection else requires
refrigeration.
Types of urine sample
Sample type
Sampling
Purpose
Random specimen
most common, taken anytime
of day
Routine screening, chemical
examination.
Morning sample
First urine in the morning,
most concentrated
Pregnancy test, microscopic
test
Midstream
Discard first few ml, collect the Culture
rest
24 hours
All the urine passed during the used for quantitative and
day and night and next day Ist qualitative analysis of
sample is collected.
substances,Protiens,AFB,
Microalbuminurea
Postprandial
2 hours after meal
Determine glucose in diabetic
monitoring
Urine examination
• Macroscopic examination
• Chemical examination
• Microscopic examination
Macroscopic examination
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Volume
Color
Transparency
Odour
PH
Urinary volume
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Normal = 600-1550ml
Polyuria- >2000ml
Oliguria-<400ml
Anuria-complete cessation of urine(<200ml)
Nocturia-excretion of urine by a adult of >500ml
with a specific gravity of <1.018 at night
(characteristic of chronic glomerulonephritis)
Color
•
Normal= clear & pale yellow
Color
 Many things affect urine color, including fluid balance, diet, medicines,
and diseases.
 Color intensity of urine correlates to concentration.
 Amber yellow
Urochrome (derivative of urobilin, produce from
bilirubin degradation, is pigment found in normal urine).
 Colorless
due to reduced concentration.
 Silver or milky appearance
 Reddish brown
 Yellow foam
Pus, bacteria or epithelial cells
Blood (Hemoglobin).
Bile or medications.
 Orange, green, blue or red
medications.
Transparency
Transparency
 Urine is normally clear. Bacteria, blood, sperm, crystals,
or mucus can make urine look cloudy.
 Is classified as clear or turbid.
 In normal urine: the main cause of cloudiness is
crystals and epithelial cells.
 In pathological urine: it is due to pus, blood and
bacteria.
 Degree of cloudiness :
 Turbidity: may be due to gross bacteriuria,
 Smoky appearance: is seen in hematouria.
 Thread-like cloudiness: is seen in sample full of mucus.
Urinary pH
• Reaction reflects ability of kidney to maintain
normal hydrogen ion concentration in plasma
& ECF
• Normal= 4.6-8
• Tested by- 1.litmus paper
2. pH paper
3. dipsticks
Odour
• Normal= aromatic due to the volatile fatty
acids
• Ammonical – bacterial action
• Fruity- ketonuria
• Maple syrup - Maple syrup disease
Chemical examination
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Proteins
PH
Sugars
Ketone bodies
Bilirubin
Bile salts
Urobilinogen
Blood
Leucocytes
Nitrite
Specific Gravity
Urine dipsticks
 Urine dipstick is a narrow plastic strip which has
several squares of different colors attached to it.
Each small square represents a component of the
test used to interpret urinalysis.
 The entire strip is dipped in the urine sample and
color changes in each square are noted. The color
change takes place after several seconds to a few
minutes from dipping the strip.
The dipstick method of chemical analysis
of urine
Specific gravity
• Depends on the concentration of various
solutes in the urine.
• Measured by-urinometer
- refractometer
- dipsticks
Specific gravity
• Normal :- 1.001- 1.040.
 Increase - Low water intake, Diabetes
mellitus, Albuminuruia, Acute nephritis.
 Decrease - Absence of ADH, Renal
Tubular damage.
Heat Test
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Procedure
Take a 5 ml test tube.
holding the tube from the bottom while heating the upper part
Fill 2/3rd with urine.
Boil upper portion for 2 minutes (lower part acts as control.
If precipitation or turbidity appears add a few drops of 10%
acetic acid.
Interpretation
• If turbidity or precipitation disappears on addition of acetic
acid, it is due to phosphates; if it persists after addition of
acetic acid then it is due to proteins
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No cloudiness = negative.
Cloudiness against dark background = traces (less
than 0.1 g/dl).
Cloudiness without granularity = + (0.1 g/dl).
Granular cloudiness=++ (0.1-0.2 g/dl)
Precipitation and flocculation = +++ (0.2-0.4 g/dl).
Thick solid precipitation = ++++ (0.5 g/dl).
Benedict’s test
Heat to boiling for 2 minutes .
Interpretation
No change of blue colour = Negative
Greenish colour = traces (< 0.5 g/dl)
Green/cloudy green ppt = + (1g/dl)
Yellow ppt = ++ (1-1.5g/dl)
Orange ppt = +++ (1.5-2g/dl)
Brick red ppt = ++++ (> 2g/d
Microscopic examination
• Microscopic urinalysis is done simply pouring the
urine sample into a test tube and centrifuging it
(spinning it down in a machine) for a few minutes.
The top liquid part (the supernatant) is discarded.
The solid part left in the bottom of the test tube (the
urine sediment) is mixed with the remaining drop of
urine in the test tube and one drop is analyzed under
a microscope
Make condenser low with partial closure of
diaphragm . First examine it under low power,
then under high power and keep on changing
the fine adjustment in order to visualize the
sediments in different planes and report as
…..cells/HPF (high power field).
Contents
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1. Cells (RBCs,WBCs, epithelial cells)
2. Casts
3. Crystals
4. Miscellaneous structures
Cells
RBCs
RBC's may appear normally shaped(pale or yellowish,
biconcave), swollen by dilute urine or crenated by
concentrated urine.
Hematuria
White Blood Cells
These appear as round granular 12-14 μm in
diameter
Pyuria refers to the presence of abnormal numbers
of leukocytes that may appear with infection in
either the upper or lower urinary tract or with
acute glomerulonephritis.
May indicate urinary tract infection UTI if more than
10/HPF
Pyuria
Epithelial Cells
• Squamous epithelia
– Large flat cell with central oval nucleus
• Transitional (bladder) epithelia
– Spindle shaped with large oval nucleus
– Maybe in sheet
• Renal tubular epithelia
– Small cell with large oval nucleus
– Most clinically significant
Squamous Epithelia
Transitional Epithelia
Renal Tubular Epithelia
RTEC
Sq EC
Casts
• Urinary casts are formed only in the distal
convoluted tubule (DCT) or the collecting duct (distal
nephron).
• The proximal convoluted tubule (PCT) and loop of
Henle are not locations for cast formation.
• Hyaline casts are composed primarily of a
mucoprotein (Tamm-Horsfall protein) secreted by
tubule cells.
Casts
The factors which favor protein cast formation are:
*low flow rate,
*high salt concentration,
*low pH,
all of which favor protein denaturation and
precipitation, particularly that of the Tamm-Horsfall
protein.
Hyaline casts can be seen even in healthy patients
cylindrical,colourless homogeneous and
transparent
Yellowish - orange colour
Granular cells (WBCs) in a clear matrix
Granules form from degenerating cells or
solidification of plasma proteins
How many casts do you see?
Crystals
• Crystalluria indicates that the urine is
supersaturated with the compounds that
comprise the crystals, e.g. ammonium,
magnesium and phosphate.
Common Crystals in Acid pH
• Amorphous urate
– Orange powder
– May clear with warming or saline
• Uric acid
– Brown lemon shaped or star shaped
– Birefringent with polarized light
• Calcium oxalate
_Colorless retractile ,octahedral ,envelope-like
structure.
Amorphous Urate
Uric acid
Uric Acid
Calcium Oxalate and Epi
61
Calcium Oxalate
62
Common Crystals in Alkaline pH
• Amorphous phosphate
– White powder
– May clear with saline
• Triple phosphate
_ in the form of prisms
_ dissolve when urine is made acidic
• Calcium carbonate
_ in the form of granules, spheres or rarely
dumbbell-shaped .
Amorphous Phosphate
Triple phosphate
Triple Phosphate
Calcium Carbonate