URINE REAGENT STRIPS

(1 PARAMETER)

Tests for Glucose 

                                                                                            

INTENDED USE:

Urine Reagent Strips-1 parameter provide a semi-quantitative determination for the presence and concentration of glucose in random urine. 

 

SUMMARY AND EXPLANATION:

Urine strip,glucose for Urinalysis are firm plastic strips to which glucose reagent areas are affixed.  The reagent area of Urine strip,glucose is ready to use upon removal from the bottle and the entire reagent strip is  disposable. When the strip is dip in random urine, the test area changes color according to the amount of glucose present in the urine.  The developing color of the test area is compare to the color blocks of the Color Chart after a specific time. Each color block corresponds to a nominal unit, which gives an indication of the amount of glucose present in the urine sample.

 

CLINICAL UTILITY:

Urine strip,glucose provides a rapid, inexpensive and visual screening procedure for the presence and concentration of glucose by examining random urine.  Results from Urine strip,glucose may also provide a guide to monitor treatment of diabetic patients.

 

PRINCIPLE:

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 from green to brown.

 

REAGENTS:  

(Based on dry weight at time of impregnation)

1.      Glucose oxidase (Aspergillus niger) >16.3% w/w

2.      Peroxidase (Horseradish) >0.6% w/w

3.      Potassioum iodide 7.0% w/w

4.      Buffer and nonreactive ingredients 60.7% w/w

 

WARNINGS AND PRECAUTIONS:

1.      Urine reagent strips are for in vitro diagnostic use only.

2.      Urine reagent strips are not for in home use. 

3.      Do not use if you are color blind. 

4.      To obtain optimal results, it is necessary to use freshly voided, well mixed and uncentrifuged urine. 

5.      The directions must be followed exactly.   

6.      Accurate timing is essential to provide optimal results. 

7.      Avoid contamination with hydrogen peroxide or any strong oxidizing agent, such as hypochlorite.1 

8.      Exposure of Urine strip,glucose to light, moisture or heat will cause deterioration      and decrease reactivity.

 

STORAGE:  

1.      Store opened and unopened bottle at temperature 15°- 30°C

         (59°- 86° F) and out of direct sunlight. 

2.      Do not use after expiration date. 

3.      The reagent strips must be kept in its original bottle with the cap tightly closed to maintain reagent reactivity. 

 

RECOMMENDED PROCEDURES FOR HANDLING URINE STRIP,GLUCOSE  

NOTE:   All warnings, precautions and proper storage procedures must be followed to avoid deterioration and insure reactivity of Urine strip,glucose. 

1.      All unused strips must remain in the original bottle.  Transfer to any other container may cause reagent strips to deteriorate and become unreactive.  

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

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 contamination substances.  

5.      When testing, dip test areas 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.

 

IMPORTANT:PROTECTION AGAINST AMBIENT MOISTURE,  LIGHT AND HEAT IS ESSENTIAL TO GUARD AGAINST ALTERED REAGENT REACTIVITY. 

Discoloration or darkening of reagent areas 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.2 

Prolonged exposure of unpreserved urine to room temperature may result in microbial contamination and bacterial consumption of urine glucose.3  Contamination of urine with hydrogen peroxide or a strong oxidizing agent, such as hypochlorite, produces false positive results.1  Store urine in clean, dry container refrigerated at 2 - 4°C.

 

MATERIALS REQUIRED BUT NOT PROVIDED: 

1.      Clean, dry container for urine sample.

2.      Commercial uirne 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 

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 do not contaminate the test sample.

 

4.      Compare reagent area to the color chart on the bottle label at exactly 30 seconds.  HOLD STRIP CLOSE TO COLOR BLOCK AND MATCH CAREFULLY.  DO NOT TOUCH THE COLOR BLOCK WITH THE TEST AREA.

 

 

QUALITY CONTROL:

For best results, it is recommended that the performance of reagent strips be confirmed by testing known positive and negative controls whenever a new bottle is first opened, or with every new batch of specimen.  In addition, commercially available control materials with varying glucose concentrations may be used for quality control.  Failure to obtain the proper low and high values in the assay of control material may indicate either reagent deterioration, instrument malfunction, or procedural errors.  It is recommended that each laboratory establish its own goals for adequate standards of performance.

 

RESULTS: 

Results with Urine strip,glucose are reported as qualitative values, by comparing the color of the test strip to the Color Chart and match it with the closest color block.  Each color block translates into a nominal value;  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.  This test is only for screening; 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.1 Turbid urine may be used; however reaction must be observed carefully.   

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.  

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.   

For urine specimens containing small glucose concentrations of 100 mg/dL, the presence of ascorbic acid in concentrations of 50 mg/dL or greater may cause false negative readings (No color developing on test area).  Ketone bodies reduce the sensitivity of the test.3  Presence of moderately high ketone levels (40 mg/dL) may also cause false negatives for urine specimens containing small glucose concentration (100 mg/dL), however the combination of such ketone levels and low glucose level is metabolically improbable in screening.  The reactivity of the glucose test decreases as the SG of the urine increases.3  Reactivity may also vary with temperature.

The glucose test is for professional use only and not for home use.  Do not use if individual performing the test is color blind, or have 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 to determine glucose concentration.

 

EXPECTED VALUES:  

The amount of glucose excreted normally is negative in this test.3  However, small amount of glucose below the sensitivity of this test may on occasion produce a color between the negative and the 100 mg/dL color blocks.1  Results of 100 mg/dL may be significantly abnormal if found consistently.

 

PERFORMANCE CHARACTERISTICS:

Sensitivity:

The sensitivity of Urine strip,glucose is 100 mg/dL or comparable to a trace reading, any concentration below 100 mg/dL will be negative.

Sensitivity will vary depending on the limitation factors of each test.  (see LIMITATIONS OF PROCEDURE)

 

Specificity:

The test is specific for glucose; no substance excreted in urine other than glucose is known to give a positive result. The reagent area does not react with lactose, galactose, fructose nor reducing metabolites of drugs (e.g., salicylates and nalidixic acid). This test may be used to determine whether the reducing substance found in urine is glucose. Reactivity may be influenced by urine specific gravity and temperature.3  In dilute urines with glucose concentrations of 40 mg/dL or less, where specific gravity is lower, the presence of small ascorbic acid at concentrations(5mg/dL or less) may cause false positive readings.

  

BIBLIOGRAPHY:

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

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

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

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

*

        Trademarks

        Serenium® is a registered trademark of E.R. Squibb & Sons.

        Pyridum®    is a registered trademark of Warner-Chilcott Laboratories.

        Azo Gantrisin® and Azo Gantanol® are registered trade marks of Roche Laboratories, Division of Hoffman-LaRoche, Inc.

        †Macrodantin® and Furadantin® are registered trade marks of Norwich-Eaton Pharmaceuticals

 

        11/16/94