timing is essential to provide optimal results. The reagent strips must be kept in the bottle with the cap tightly closed to maintain reagent reactivity. To obtain optimal results, it is necessary to use fresh, well-mixed, uncentrifuged urine.
1. In the porphyrias, the urine contains increased
amounts of porphyrins and porphobilinogens and
may not contain increased amounts of DAL or ALA.
2. ALA and DAL excretion is elevated in acute intermittent
porphyria, a hepatic porphyria that is aggravated by
alcohol, barbiturates, and other drugs affecting the
1. ALA or DAL will be present in the urine
2. Porphyrins may or may not be present in the urine.
Other Conditions with Increased Levels of Porphyrins
¾ Carbon tetrachloride or benzene poisoning.
1. During menstruation and pregnancy, porphyrins may
2. Drugs that can cause false-positive test are:
Hematuria can be gross, urine appears reddish due to blood,
it can also be microscopic, when it is not visible to the naked
eye, here various tests are performed for confirmation.
In one test tube, mix 2 mL of 10% acetic acid, 5 mL of
urine and 5 mL ether. In a second test tube, place 5 mL of
95% alcohol, 2 mL fresh hydrogen peroxide and a pinch
of powdered guaiac. Now pour the guaiac solution slowly
down the side of the first tube. Blood in the urine causes
blue color to appear at the zone of contact between the
Saturate 2 mL of glacial acetic acid with benzidine and pour
off the clear supernatant fluid. Add 1 mL of fresh hydrogen
peroxide and 2 mL of urine. Development of blue color
indicates a positive test (if the blue color develops before
the addition of urine, the glassware is contaminated).
b. Local disorders of kidney and genitourinary tract.
1. Acute and chronic glomerulonephritis
2. Systemic lupus erythematosus
6. Allergic nephropathies (Henoch-Schonlein’s purpura)
7. Thrombotic thrombocytopenic purpura
Normal values: Negative for bacteria.
Explanation of test: There are two methods that are used
to detect bacteria in the urine during routine urinalysis—
microscopic examination and clinical testing. The
sediment when examined microscopically can reveal
bacteria when present. Chemical dipstick testing is also
commonly done. The nitrite area in the multiple reagent
strip, is calibrated so that any shade of pink color that
develops within 30 seconds indicates an amount of nitrite
or more organisms per mL in the urine
1. A first morning specimen is preferred because urine
that has been in the bladder for several hours is
more likely to yield a positive result. A clean catch or
midstream urine is needed to avoid bacterial contamination.
2. Follow procedure as stated by the dipstick manufacturer.
1. The finding of 20 or more bacteria per high power field
may indicate a urinary tract infection.
2. The presence of only a few bacteria should be
interpreted with caution and suggests a urinary tract
infection that cannot be confirmed or excluded until
more definitive studies, such as cultures and sensitivity
3. A positive result from the nitrite test is a reliable
indication of a significant bacteriuria and is an
4. A negative result should never be interpreted as
indicating absence of bacteriuria because:
a. If an overnight sample was not used, there may
have been insufficient time for the conversion of
nitrate to nitrite to have occurred.
b. There may be a rare instance when nitrite does
not appear in urine, and a person of this type
could have significant bacteria without a positive
c. Some strains of urinary pathogens do not produce enzymes necessary to change nitrate to
nitrite and can cause a negative result.
Rapidity of diagnosis is of utmost importance in today’s
Many manufacturers now provide rapid strip test
(qualitative and semiquantitative). Important among
Strip Tests from Boehringer-Knoll Limited
Various other combinations or single test strips are also
available, e.g. pertaining only to liver/kidney disorders.
Strip Tests from Roche Limited
Now with improved pad order and efficacy.
c. Ictotest (tablets) Bilirubin
d. Keto-diastix Glucose and ketones pH,
e. Multistix protein, glucose, ketones, bilirubin, blood,
f. Uristix Glucose and protein
g. Combistix SG Glucose, protein, pH and specific gravity
h. Multistix SG All of (E) + Specific gravity
i. Neostix 3 Blood, glucose and protein
MULTIPLE REAGENT STRIPS FOR URINALYSIS
Tests for glucose, bilirubin, ketone (acetoacetic acid),
specific gravity, blood, pH, protein and urobilinogen in
urine. Refer to the carton and bottle label for specific
reagent areas on the product you are using.
Summary and Explanation/Intended Use
Bayer reagent strips for urinalysis are firm plastic strips
to which are affixed several separate reagent areas.
Depending on the product being used, Bayer reagent strips
provide tests for glucose, bilirubin, ketone (acetoacetic
a. Combur 9 test Leukocytes, nitrite, pH, protein, glucose,
ketone bodies, urobilinogen, bilirubin, blood
b. Combur 8 test All of A except leukocytes
c. Combur 7 test All of B except nitrite
d. Combur 6 test All of C except bilirubin
e. Combur 4 test Protein, glucose urobilinogen, blood
f. Ecur test Protein, glucose, blood
g. Combur test Glucose, protein, pH
results may provide information regarding the status of
carbohydrate metabolism, kidney and liver function, and
The reagent test areas on Bayer Reagent strips are ready
to use upon removal from the bottle and the entire reagent
strip is disposable. The strips may be read visually, requiring
no additional laboratory equipment for testing. Certain
configurations of strips may also be read instrumentally,
using the Clinitek® family of urine chemistry analyzers and
the appropriate program module or program card.
The directions must be followed exactly. Accurate
timing is essential to provide optimal results. The reagent
strips must be kept in the bottle with the cap tightly closed
to maintain reagent reactivity. To obtain optimal results, it
is necessary to use fresh, well-mixed, uncentrifuged urine.
Chemical Principles of the Procedure
This test is based on a double sequential enzyme reaction.
One enzyme, glucose oxidase, catalyzes the formation of
gluconic acid and hydrogen peroxide from the oxidation
of glucose. A second enzyme, peroxidase, catalyzes the
reaction of hydrogen peroxide with a potassium iodide
chromogen to oxidize the chromogen to colors ranging
This test is based on the coupling of bilirubin with
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