Catalogue Number C-U 1

URINE REAGENT STRIPS

(1 PARAMETER)

Test for Urine Occult Blood

INTENDED USE

Urine Reagent Strips C-U 1 provide a semi-quantitative determination for the presence and concentration of occult blood in urine.  The presence of occult blood in urine is important because it is indicative of bleeding  which can be caused by a variety of abnormal conditions such as hematuria, hemoglobinuria, myoglobinuria and cancer.

SUMMARY AND EXPLANATION:

 C-U 1  for urinalysis are firm plastic strips, each strip having a reagent area for detection of occult blood affixed.  The reagent area of  C-U 1  is ready to use upon removal from the bottle and the entire reagent strip is disposable.  When the strip is dipped in urine, the test area changes color according to the amount of hemoglobin and its derivatives that are present in the urine.  The colors of the test area is compared to the color blocks of the Color Chart directly on the bottle.  No additional instrumentation is required.

PRINCIPLE:

BLOOD:  This test is based on the peroxidase-like activity of hemoglobin, which catalyzes the reaction of cumene hydroperoxide 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.

REAGENTS:

(Based on dry weight at time of impregnation)

BLOOD:  5.0% w/w cumene hydroperoxide; 4.0% w/w 3,3’,5,5’-tetramethylbenzidine; 48.0% w/w buffer; 43.0% w/w nonreactive ingredients.

WARNINGS AND PRECAUTIONS:

1.       C-U 1   is for in vitro diagnostic use only

2.       C-U 1  is not for home use.

3.      Do not use if you are color blind.

STORAGE:

1.      Store open and unopened bottle at temperature 15°-30°C (59°-  86°F) and out of direct sunlight.

2.      Do not use after expiration date.

RECOMMENDED PROCEDURES FOR HANDLING  C-U 1 :

1.      All unused strips must remain in original bottle. Transfer to

         any other container may cause reagent strips to deteriorate and become nonreactive.

2.      Do not remove desiccant(s) from the bottle.  Replace cap immediately and tightly after removing reagent strip to test.

3.      Do not combine urine strips with different lot numbers together.

4.      Do not touch test areas of the reagent strip.  Work areas and specimen containers should be free of detergents and other        contaminating substances.

5.      When testing, dip test area in urine completely, but briefly, to   avoid dissolving out the reagents.  Read test results carefully at the time specified, in a good light and with the test area held near, but not touching the Color Chart on the bottle label.

Discoloration or darkening of reagent area may indicate deterioration. If this is evident, or if test results are questionable or inconsistent with expected finding, the following steps are recommended: (1) Confirm that the product is within the expiration date shown on the label. (2) Check performance against known positive control materials. (3) Retest with fresh product.

SPECIMEN COLLECTION AND PREPARATION:  

Collect random urine according to NCCLS GP16-T guideline in a clean container and test as soon as possible.  If testing cannot be done within an hour after voiding, it is recommended that the urine sample be refrigerated immediately at 2 - 4°C and let it return to room temperature before testing.1

Prolonged exposure of unpreserved urine to room temperature may result in microbial proliferation.2 Bacterial growth from contaiminating organisms may cause false positive blood reactions from the peroxidase produced.3    Store urine in clean, dry container and refrigerated at 2 - 4°C.

MATERIALS PROVIDED:

1.      1 bottle containing 100 strips of  C-U 1 .

2.      A visual comparison Color Chart for reading test results is        printed on the bottle.

MATERIALS REQUIRED BUT NOT PROVIDED:

1.      Clean, dry container for urine sample.

2.      Commercial urine controls

3.      Timer or watch capable of measuring accurately in seconds.

PROCEDURE:  MUST BE FOLLOWED EXACTLY TO ACHIEVE RELIABLE TEST RESULTS.

NOTE:  In accordance with CDC guidelines on proper handling of    bodily fluids, it is recommended that gloves be worn when performing this test.

1.      Collect random urine specimen in a clean, dry container.  Mix well immediately before testing.  If urine specimens are not    tested within 1  hour after voiding store at 2-4°C and bring to room temperature before testing.

2.      Remove one strip from bottle and close the cap immediately.  Hold the plastic end of the strip. Completely immerse reagent   areas of the strip in urine sample and remove immediately to avoid dissolving out reagents.

3.      Remove the urine strip slowly avoiding splashing effect.  Run the edge of the strip against the rim of the urine container to remove excess urine.

 Note:  In the case that urine sample splashes onto gloves or body, rinse well with water. Use new gloves when testing a different urine sample. Make sure urine that may have contaminated gloves from previous sample does not contaminate the test sample.

4.      Compare reagent area to the color chart on the bottle label and   read as specified.  HOLD STRIP CLOSE TO COLOR BLOCK       AND MATCH          CAREFULLY.  DO NOT TOUCH THE COLOR         BLOCK WITH THE TEST AREA. 

QUALITY CONTROL:

For best results, performance of reagent strips should be confirmed by testing known negative and positive controls whenever a new bottle is first opened.  Negative and positive controls may also be randomly hidden in each batch of specimens tested.  Each laboratory should establish its own goals for adequate standards of performance, and should question handling and testing procedures if these standards are not met.

RESULTS:

Results with URINE REAGENT STRIPS are obtained in clinically meaningful units directly from the Color Chart comparison.  The color blocks represent nominal values; actual values will vary around the nominal values.

LIMITATIONS OF PROCEDURE:

As with all laboratory tests, definitive diagnostic or therapeutic decisions should not be based on any single result or method. All positive results should be confirmed by a quantitative method where accuracy and sensitivity are greater.

High blood concentration in sample may mask color development or cause atypical color formation.2 Turbid urine may be used; however reaction must be observed carefully. 

Substances that cause abnormal urine color, such as Serenium®*, drugs containing Azo dyes (e.g., Pyridium®*, Azo Gantrisin®*,Azo Gantanol®*), nitrofurantoin (Macrodantin®†, Furadantin®†), and riboflavin, may affect the readability of reagent areas on urinalysis reagent strips.4  The color development on the reagent pad may be masked or a color reaction may be produced on the pad that could be interpreted as a false positive. 

BLOOD:  The significance of the Trace reaction may vary among patients, and clinical judgment is required for assessment in an individual case.  Development of green spots (intact erythrocytes) or green color (free hemoglobin/myoglobin) on the reagent area within 60 seconds indicated the need for further investigation.  Blood is often, but not always found in the urine of menstruating females.

 C-U 1  is for professional use only and not for home use.  Do not use if individual performing the test is color blind, or has any vision impairment.  Do not combine urine strips with different lot numbers together at any time.  Contamination of both urine sample and reagent strips must be avoided. This test is inappropriate for neonatal urine specimens and cannot be used. 

EXPECTED VALUES:  

BLOOD:  This test is negative for normal urine.  Any green spots or green-blue color developing of the reagent area is significant and the urine should be examined further.

 PERFORMANCE CHARACTERISTICS:

The performance characteristics of  C-U 1  urine reagent strips have been determined both in the laboratory and in clinical tests.  Parameters of importance to the user are sensitivity, specificity, accuracy and precision.  Generally, this test has been developed to be specific for the constituent to be measured with the exception of interferences listed previously.  (see LIMITATIONS OF PROCEDURE).

For visually read strips, accuracy is a function of the manner in which the color block on the bottle label are determined and the discrimination of the human eye in reading the test.  Precision is difficult to assess in a test of this type because of the variability of the human eye.  It is for this reason that users are encouraged to developed their own standards of performance.

Sensitivity:

BLOOD:   At the time of reagent manufacture, the test has a sensitivity to free hemoglobin of 0.015 mg/dl or 5 intact red blood cells/mL of urine.  The sensitivity of this test may be reduced in urine with high specific gravity.  The test is slightly more sensitive to free hemoglobin and myoglobin than to intact erythrocytes. 

BIBLIOGRAPHY:

1.      Free, H.M.: Routine Urinalysis and Collection, Transportation,         and    Preservation of Urine Specimen; NCCLS doc.GP16T: 1993.

2.      Tietz, N.W.: Clinical Guide to Laboratory Tests; 2nd ed.: W.B           Saunders   Company; 1990.

3.      Tiez, N.W.: Clinical Chemistry; 2nd ed.: W.B Saunders    Company; 1994.

4.      Young, D.S.: Effects of Drugs on Clinical Laboratory Tests; 3rd         ed.  AACC       Press; 1990.