Device Description
URS-1B strips for Urinalysis are firm plastic strips to which a blood reagent area is affixed. URS-1B strips are packaged along with a drying agent in an aluminum pouch. Each strip is ready to use upon removal from the pouch. The entire reagent strip is disposable. Results are obtained by direct comparison of the test strip with the color blocks printed on the pouch.
Warnings and Precautions
1. Urine reagent strips are for in vitro diagnostic use only. They have been determined to be nonhazardous under the guidelines issued by OSHA in 29 CFR 1910.1200(d).
2. Any visual impairment, such as color blindness, will affect accuracy of reading the results
3. To obtain best results, use fresh urine.
4. Follow directions exactly.
5. For optimal results, accurate timing is essential
6. Exposure of URS-1B to light, moisture, or heat will cause deterioration and decrease reactivity.
Conditions Under Which the Device Should and Should Not be Used
1. Comparison to the color chart is dependent on the interpretation of the individual. It is therefore recommended that all users be tested for color blindness.
2. Work areas and specimen containers should be free of contaminating substances.
3. When testing, dip test areas in urine completely, but briefly, to avoid dissolving out the reagents. Read test results carefully at specified time in a good light with the test area held near the color chart.
Setup Instructions
Work areas and specimen containers should be free of contaminating substances. Collect urine in a clean container and test as soon as possible. If testing cannot be performed within one hour, refrigerate the specimen immediately. Allow refrigerated specimen to return to room temperature before testing.
Reading the Results
hen a strip is dipped in urine, the test area changes color according to the amount of blood present in the urine. The developing color of the test area is compared to the color blocks on the color chart after time specified.
Storage and Handling
NOTE: All warnings, precautions, and proper storage procedures must be followed to avoid deterioration and insure reactivity of URS-1B.
1. Store pouch at temperatures between 15°- 30°C (59°- 86° F) and out of direct sunlight.
2. Do not use after expiration date
3. Do not touch test areas of the reagent strip.
Materials Provided
1. Aluminum pouch containing one strip of URS-1B.
2. A visual comparison color chart for reading test results is printed on the pouch.
Materials Required But Not Provided
1. Clean, dry container for urine collection. 2. Timer or watch capable of measuring accurately in seconds.
Test Procedure (Must be followed exactly to achieve reliable test results)
NOTE: A positive result from a screening is considered to be a screened presumptive or indeterminate result and should never be interpreted as final without a follow-up with a health care provider, confirmation testing, or both.
1. Collect urine specimen in a clean, dry container. Mix well immediately before testing. If urine specimens are not tested within 1-hour store at 2-4°C and bring to room temperature before testing.
2. Remove strip from pouch for immediate use. Hold the plastic end of the strip. Completely immerse reagent area of the strip in urine sample and remove immediately to avoid dissolving out reagent area.
3. Remove the strip slowly avoiding any spilling. Run the edge of the strip against the rim of the urine container to remove excess urine.
4. Exactly 60 seconds after removing from the specimen, compare reagent area to the color chart on the pouch. (Hold strip close to color block and match carefully. Do not touch the color block with the test area
Results
Results with URS-1B are reported as qualitative values, by comparing the color of the test strip to the Color Chart and matching it with the closest color block.
Limitations of Test
1. The sensitivity of the blood test is reduced in urine with high specific gravity and/or high ascorbic acid content. Microbial peroxidase, associated with urinary tract infection may cause false positive reactions.
2. This test is only for screening; all positive results should be confirmed by a health care provider and/or a quantitative method where accuracy and sensitivity are greater.
3. Interpretation of results will depend upon several factors: the variability of color perception; the presence or absence of inhibitory factors typically found in urine, and the specific gravity; and the lighting conditions under which the product is used.
4. Do not use if individual performing the test is color blind, or has any vision impairment.
5. Contamination of both urine sample and reagent strips must be avoided.
Expected Values
Any green spots or green color developing on the reagent area within 40 seconds is significant and the urine should be examined further. Blood is frequently, but not invariably found in the urine of menstruating females.
Performance and Characteristics
As with any visual test, accuracy is a function of the manner at which the color blocks on the pouch 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.
At the time of reagent manufacture, the test when read as instructed has a sensitivity to free hemoglobin of 0.015 mg/dl or 5-10 intact red blood cells / 1/4 l urine. The test is slightly more sensitive to free hemoglobin and myoglobin than to intact erythocytes.
Troubleshooting
(Protection of URS-1B against ambient moisture, light and heat is essential to guard against altered reagent activity).
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 pouch.
(2) Check performance against known positive control materials.
(3) Retest with fresh product.
BIBLIOGRAPHY
1. Free, A.H and Free, H.M.: Urinalysis, Critical Discipline of Clinical Science. CRC Crit. Rev. Clin. Lab. Sci. 3(4): 481- 531; (1972).
2. Yoder, J.Adams, E.C., and Free. H.M.: Simultaneous Screening for Urinary Occult Blood, Protein, Glucose, and pH. Amer. J. Med Tech. 31:285; (1965).
3. Tietz, N.W.: Clinical Guide to Laboratory Tests; W.B. Saunders Company, (1976)
4. Burtis, C.A. and Ashwood, E.R.: Tietz Textbook of Clinical Chemistry 2nd Ed. 2205; (1994).
5. Henry, J.B. et al.: Clinical Diagnosis and Management by Laboratroy Methods, 16th Ed. Philadelphia: Saunders; (1979).
