This is the presence of albumin in the urine.
Albumin is a protein, consisting of serum albumin
and serum globulin that has been eliminated from
the blood plasma. It contains carbon, hydrogen,
nitrogen, oxygen, and sulfur. Its exact composi-
tion has not been determined.
Urinary albumin does not necessarily indicate
diseased kidneys; it may reflect reactions to toxic
and nontoxic substances originating within the
body. Albuminuria is frequently found in young
men who have no other signs of disease. This con-
dition is usually transitory. However, albuminuria
usually is of clinical significance and generally re-
quires further examination.
Methods for Measuring Albumin in Urine
The test is accomplished by means of test
strips. Since practically all urine is tested for both
glucose and albumin, the tests are combined in
the multitest strips. If the strips are unavailable,
or positive for albumin, the sulfosalicylic acid
method of albumin determination may be used.
Sulfosalicylic Acid Method of Albumin
If the fresh specimen is clear, the test may
be run without centrifuging. If the
specimen is cloudy, centrifuge about 15 ml
at 2,000 rpm for 5 minutes.
Pour 2.5 ml of clear urine into a test tube
measuring 16 mm x 150 mm.
Add 7.5 ml of 3 percent sulfosalicylic acid
to the urine.
Mix by inversion and let stand 10 minutes
A white turbidity indicates albuminuria.
Compare the specimen with the standards
and report as indicated, i.e., 1, 5, etc.
CAUTION: The centrifuge is a carefully
balanced machine, and efforts should be made to
maintain that balance. Specimens should be
placed directly opposite each other in the machine.
If only one urine specimen is being centrifuged,
place a tube containing an equivalent weight of
water directly opposite the urine.
MICROSCOPIC EXAMINATION OF
Usually performed in addition to routine pro-
cedures, this examination requires a degree of skill
that can be acquired only through practice under
the immediate supervision of a competent techni-
cian. The specimen should be as fresh as possible,
since red cells and many formed solids tend to
disintegrate upon standing, particularly if the
specimen is warm or alkaline.
Mix the specimen well.
Pour 15 ml of urine into a conical cen-
trifuge tube and centrifuge at 1,500 rpm for
Invert the centrifuge tube and allow all of
the excess urine to drain out. DO NOT
S H A K E T H E T U B E W H I L E I N-
VERTED. Enough urine will remain in the
tube to resuspend the sediment. Too much
urine remaining will cause diluting of the
sediment and difficulty in reading.
Resuspend the sediment by tapping the bot-
tom of the tube.
With a medicine dropper, mount one drop
of the suspension on a slide and cover it
with a coverslip.
Place the slide under the microscope and
scan with the low-power objective and sub-
Switch to the high-power objective for
detailed examination of a minimum of 10
to 15 fields.
Clinically Significant Findings
LEUKOCYTESNormally, 0 to 3 leukocytes
per high-power field will be seen on microscopic
examination. More than 3 cells per high-power
field probably indicates disease somewhere in the
urinary tract. Estimate the number of leukocytes
present per high-power field and report it as the
estimated number per high-power field.
ERYTHROCYTESThese cells are not
usually present in normal urines. If erythrocytes
are found, estimate their number per high-power
field and report it. Erythrocytes maybe differen-
from white cells in several ways:
White cells are larger than red cells.
When focusing in with the high-power
lens, the red cells show a distinct circle; the
white cells tend to appear granular and the
nucleus may be visible.