Product Manual

pH:
Expected values: The normal pH of urine can range from 4.6 to 8.0.
Certain dietary conditions can produce acid or alkaline urines, which can
be useful in the treatment of some calculi.
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Performance characteristics: The pH test area measures pH values
from 5–8.5 visually and 5–9 instrumentally, generally to within one unit of
the expected result. pH readings are not affected by variations in the uri-
nary buffer concentration.
Limitations: Bacterial growth by certain organisms in a specimen may
cause a marked alkaline shift (pH >8.0), usually because of urea conver-
sion to ammonia.
SPECIFIC GRAVITY:
Expected values: The normal SG of urine ranges from 1.001–1.035. If
the specific gravity of a random urine is 1.023 or greater, the concentrat-
ing ability of the kidneys can be considered normal.
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Performance characteristics: This test permits determination of urine
specific gravity between 1.000 and 1.030. In general, it correlates within
0.005 with values obtained with the refractive index method. For in-
creased accuracy, 0.005 may be added to readings from urines with pH
≥6.5. Strips read instrumentally are automatically adjusted for pH by the
instrument. The Bayer SG test is not affected by the presence of radio-
paque dyes as are the refractive index, urinometer, and osmolality methods.
Limitations: The Bayer SG test is dependent on ions in urine and results
may differ from those obtained with other specific gravity methods when
certain nonionic urine constituents, such as glucose, are present. Highly
buffered alkaline urines may cause low readings, while the presence of
moderate quantities of protein (100–750 mg/dL) may cause elevated
readings.
BILIRUBIN:
Expected values: Normal adult urine contains about 0.02 mg/dL of biliru-
bin, which is not detectable by even the most sensitive methods. Even
trace amounts of bilirubin are sufficiently abnormal to require further inves-
tigation.
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Since very small amounts of bilirubin (0.1 mg/dL or greater)
may be found in the earliest phases of liver disease, the user must con-
sider whether the sensitivity of Bayer Reagent Strips to bilirubin is suffi-
cient for the intended use. When very small amounts of bilirubin in urine
are sought (e.g., in the earliest phase of viral hepatitis), ICTOTEST
®
Reagent Tablets should be the method of choice.
Sensitivity: 0.4–0.8 mg/dL bilirubin
Performance characteristics: The test is specific for bilirubin and will not
react with any other substance normally excreted in urine.
Limitations: Indican (indoxyl sulfate) can produce a yellow-orange to red
color response that may interfere with the interpretation of a negative or
positive reading. Metabolites of Lodine (etodolac) may cause false posi-
tive or atypical results. Atypical colors (colors that are unlike the negative
or positive color blocks shown on the Color Chart) may indicate that biliru-
bin-derived bile pigments are present in the urine sample and may be
masking the bilirubin reaction. These colors may indicate bile pigment
abnormalities and the urine specimen should be tested further (e.g.,
ICTOTEST Reagent Tablets).
UROBILINOGEN:
Expected values: Urobilinogen is normally present in urine at concentra-
tions up to 1.0 mg/dL (1 Ehrlich Unit/dL). A result of 2.0 mg/dL represents
the transition from normal to abnormal, and the patient and/or urine spec-
imen should be evaluated further for hemolytic and hepatic disease.
Evaluation of both the bilirubin and urobilinogen results helps in the differ-
ential diagnosis of jaundice, as well as other liver and biliary disorders.
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Performance characteristics: This test area will detect urobilinogen in
concentrations as low as 0.2 mg/dL (0.2 EU/dL) in urine. The absence of
uroblinogen in the specimen cannot be determined.
Limitations: The test pad may react with interfering substances known to
react with Ehrlich’s reagent, such as ρ-aminosalicylic acid and sulfon-
amides. Atypical color reactions may be obtained in the presence of high
concentrations of ρ-aminobenzoic acid. False negative results may be
obtained if formalin is present. Strip reactivity increases with temperature;
the optimum temperature is 22°–26°C (72°–79°F). The test is not a
reliable method for the detection of porphobilinogen.
HELPFUL HINTS:
• Do not remove the strip from the bottle until immediately before it is to be
used for testing. Replace the cap immediately and tightly after removing
the reagent strip. Do not touch the test areas of the strip.
• Do not read any test pad after 2 minutes; color changes that occur after
this time are of no diagnostic value.
• Discoloration or darkening of the test pads may indicate deterioration. If
this is evident, or if test results are questionable or inconsistent with
expected findings, the following steps are recommended: (1) confirm that
the product is within the expiration date shown on the label; (2) check
performance against known negative and positive control materials; (3)
retest with fresh product. If proper results are not obtained, consult your
local product representative, or contact the Customer Service
Department, by calling 1-877-229-3711 (U.S. only), for advice on testing
technique and results.
• Contamination of the urine specimen with skin cleansers containing chlor-
hexidine may affect protein (and to a lesser extent specific gravity and
bilirubin) test results. The user should determine whether the use of such
skin cleansers is warranted.
• It is especially important to use fresh urine to obtain optimal results with
the tests for bilirubin and urobilinogen, as these compounds are very
unstable when exposed to room temperature and light.
CHEMICAL PRINCIPLES OF PROCEDURES AND INGREDIENTS:
(based on dry weight at time of impregnation)
Protein: This test is based on the protein-error-of-indicators principle. At a
constant pH, the development of any green color is due to the presence
of protein. Colors range from yellow for “Negative” through yellow-green
and green to green-blue for “Positive” reactions. Ingredients: 0.3%
w/w tetrabromphenol blue; 97.3% w/w buffer; 2.4% w/w nonreactive
ingredients.
Blood: This test is based on the peroxidase-like activity of hemoglobin,
which catalyzes the reaction of diisopropylbenzene dihydroperoxide and
3,3',5,5'-tetramethylbenzidine. The resulting color ranges from orange
through green; very high levels of blood may cause the color development
to continue to blue. Ingredients: 6.8% w/w diisopropylbenzene dihydro-
peroxide; 4.0% w/w 3,3',5,5'-tetramethylbenzidine; 48.0% w/w buffer;
41.2% w/w nonreactive ingredients.
Leukocytes: Granulocytic leukocytes contain esterases that catalyze the
hydrolysis of the derivatized pyrrole amino acid ester to liberate 3-hydroxy-
5-phenyl pyrrole. This pyrrole then reacts with a diazonium salt to produce
a purple product. Ingredients: 0.4% w/w derivatized pyrrole amino acid
ester; 0.2% w/w diazonium salt; 40.9% w/w buffer; 58.5% w/w nonreactive
ingredients.
Nitrite: This test depends upon the conversion of nitrate (derived from the
diet) to nitrite by the action of Gram negative bacteria in the urine. At the
acid pH of the reagent area, nitrite in the urine reacts with ρ-arsanilic acid
to form a diazonium compound. This diazonium compound in turn couples
with 1,2,3,4-tetrahydrobenzo(h)quinolin-3-ol to produce a pink color. Ingre-
dients: 1.4% w/w ρ-arsanilic acid; 1.3% w/w 1,2,3,4-tetrahydrobenzo(h)-
quinolin-3-ol; 10.8% w/w buffer; 86.5% w/w nonreactive ingredients.
Glucose: 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, per-
oxidase, catalyzes the reaction of hydrogen peroxide with a potassium
iodide chromogen to oxidize the chromogen to colors ranging from green
to brown. Ingredients: 2.2% w/w glucose oxidase (microbial, 1.3 IU);
1.0% w/w peroxidase (horseradish, 3300 IU); 8.1% w/w potassium iodide;
69.8% w/w buffer; 18.9% w/w nonreactive ingredients.
Ketone: This test is based on the development of colors ranging from buff-
pink, for a negative reading, to maroon when acetoacetic acid reacts with
nitroprusside. Ingredients: 7.1% w/w sodium nitroprusside; 92.9% w/w
buffer.
pH: This test is based on a double indicator principle that gives a broad
range of colors covering the entire urinary pH range. Colors range from
orange through yellow and green to blue. Ingredients: 0.2% w/w methyl
red; 2.8% w/w bromthymol blue; 97.0% w/w nonreactive ingredients.
Specific Gravity: This test is based on the apparent pKa change of cer-
tain pretreated polyelectrolytes in relation to ionic concentration. In the
presence of an indicator, colors range from deep blue-green in urine of low
ionic concentration through green and yellow-green in urines of increasing
ionic concentration. Ingredients: 2.8% w/w bromthymol blue; 68.8% w/w
poly (methyl vinyl ether/maleic anhydride); 28.4% w/w sodium hydroxide.
Bilirubin: This test is based on the coupling of bilirubin with diazotized
dichloroaniline in a strongly acid medium. The color ranges through vari-
ous shades of tan. Ingredients: 0.4% w/w 2,4-dichloroaniline diazonium
salt; 37.3% w/w buffer; 62.3% w/w nonreactive ingredients.
Urobilinogen: This test is based on the Ehrlich reaction in which ρ-diethyl-
aminobenzaldehyde in conjunction with a color enhancer reacts with uro-
bilinogen in a strongly acid medium to roduce a pink-red color.
Ingredients: 0.2% w/w ρ-diethylaminobenzaldehyde; 99.8% w/w nonre-
active ingredients.