Diagnosis
Intended use
UTItest 5V urine reagent strips provide a quick way to test for leukocytes, protein, nitrites and blood in the urine, and to test urine pH. The greater the number of positive results, the stronger the indication of urinary tract infection, with a positive protein result indicating possible kidney involvement.
The advantage of the QuicklyTest UTItest 5V is that all five indicators of UTI are present,
minimizing any confusion caused by the presence of false positives or false negatives.
The test strips are intended primarily for use by health care professionals, but can also be used for self-testing at home. Positive results should generally be followed up by lab cultures and concerns discussed with a doctor.
Test Principles And Limitation
Leukocytes:
The test reveals the presence of granulocyte esterases. These esterases cleave an indoxyl ester, and the indoxyl so liberated reacts with a diazonium salt to produce a violet dye.
Leukocyte esterase results may be positive in the absence of observable cells if the leukocytes have lysed. Positive results may occasionally be found with random specimens from females due to contamination of the specimen by vaginal discharge. Elevated glucose concentrations (55-110 mmol/L) or high specific gravity may cause decreased test results. The presence of cephalexin, cephalothin, or tetracycline may cause decreased reactivity, and high levels of the drug may cause a false negative reaction. The test area does not react with lymphocytes.
Nitrites:
The test is based on the principle of Griess’s test and is specific to nitrites. Any degree of uniform pink colour development should be interpreted as a positive.
Positive results of the nitrites test suggests the presence of 105 (100,000) or more organisms per mL of urine, but colour development is not proportional to the number of bacteria present. A negative result does not in itself prove that there is no significant bacteriuria. Negative results may occur when urinary tract infections are caused by organisms that do not contain reductase to convert nitrate to nitrite; when urine has not been retained in the bladder long enough (4-8hrs) for reduction of nitrate to occur; or when dietary nitrate is absent, even if organisms containing reductase are present and bladder incubation is ample. Ascorbic acid concentrations of 2.8mmol/L or greater may cause false negative results with specimens containing nitrite ion concentrations of 35μmol/L or less.
Protein:
The test is based on the principle of the protein error of a pH indicator.
The reagent area is sensitive to albumin. An elevated pH (up to 9) may affect the test. If the residue of disinfectant containing quaternary ammonium groups or chlorhexidine is present in the urine collection container, this may lead to a false positive result.
pH:
This test contains a mixed indicator which assures a marked change in colour between pH5 and pH8.5. It may be necessary to repeat this test a number of times with a space of 3 hours between tests to determine the prevailing pH. High or low pH or wild swings in pH may indicate presence of bacteriuria.
Blood:
Haemoglobin and myoglobin catalyze the oxidation of the indicator by means of organic hydroperoxide contained in the test paper.
This test is highly sensitive to haemoglobin and thus complements microscopic examination. The sensitivity of this test may be reduced in urine with high specific gravity. The test is equally sensitive to myoglobin as to haemoglobin (Haemoglobin concentration of 150-620 μg/L is approximately equivalent to 5-15 intact red occult blood cells per microlitre). Captopril and Lodine may also cause decreased reactivity. Blood is often found in the urine of menstruating females. Certain oxidizing contaminants, such as hypochlorite, may produce false positive results. Microbial peroxidase associated with urinary tract infection may cause a false positive reaction. Ascorbic acid concentrations of 2.0mmol/L or greater may cause false negatives at the trace levels.
Sensitivity And Range
Sensitivity is dependent upon the presence or absence of interfering specimens.
Reagents Composition
Based on the dry weight content of each reagent in 100 strips:
Leukocytes: indoxyl ester 1.4mg, diazonium salt 0.7mg;
Nitrite: sulfanilamide 0.65mg, N-(naphthyl)-ethylenediammonium dihydrochloride 0.45mg;
Protein: tetrabromphenol blue 0.36mg;
pH: methyl red 0.06mg, bromthymol blue 1.3mg;
Blood: cumene hydroperoxide 35.2mg, 3,3',5,5' -Tetramethylbenzidine 15.0mg.
Precautions
1. HANDLING: Use a clean container to collect urine. False-positive readings for Blood can result from residues of strongly oxidizing disinfectants in the specimen collection container. Do not add preservatives to the urine to be tested.
2. OPERATION: Incorrect results may be obtained when you shake the strip in specimen container. Dip for approx. two seconds. If the dipping time is too short or too long, the results may be unpredictable.
Specimen Collection And Preparation
Collect urine in a clean container and test as soon as possible. Do not centrifuge. Use of urine preservatives is not recommended. If testing cannot be performed within one hour after voiding, refrigerate the specimen immediately. Allow refrigerated specimen to return to room temperature before testing.
Test Procedure
1. Remove one strip from the bottle at a time and replace cap tightly.
2. Completely immerse reagent areas of the strip in fresh, well mixed urine. Remove the strip immediately to avoid the dissolving out of reagent areas.
3. While removing, tap the strip against the rim of the urine container to remove excess urine. Blot the urine strip on a long edge, on absorbent paper. Avoid running over (contamination from adjacent reagent pads).
4. Compare each reagent area to its corresponding colour blocks, shown on the colour chart and read at the times specified. Proper read-time is critical for optimal results.
5. Obtain results by direct colour chart comparison.
NOTE: All reagent areas may be read between 1-2 minutes for differentiating a positive sample from a negative sample. Changes in colour after 2 minutes are of no diagnostic value.
Quality Control
For best results, performance of reagent strips should be confirmed by comparing with known negative and positive specimens or controls. This procedure is recommended after use of every 25 urine strips and for each change in urine strip containers and lot. User/labs should establish their own goals for performance standards.
Results
Results are obtained by direct comparison of the colour chart printed on the container label. The colour chart represents nominal values. Actual values will vary around the nominal values.
Handling Care
Improper storage may cause insufficient performance of test strips. Return to room temperature before use. Do not use deteriorated, discoloured or blackened test strips. Avoid contamination by volatile chemicals. Do not touch test papers of reagent strips.
Please Note
On principle, diagnosis or therapy should not be based on one test result alone but should be established in the context of all other medical findings. Knowledge of the effects of drugs or their metabolites upon the individual tests is not yet complete. In doubtful cases, it is therefore advisable to repeat the test after discontinuing a particular drug. Large amounts of ascorbic acid in the urine can produce artificially low to false-negative results for blood and nitrites.
Storage and Stability
Store at temperatures between 2 C to 30 C avoiding humidity, direct sunlight, or heat. Store only in the original bottle. Do not remove desiccants. Do not remove a strip from the bottle until immediately before it is to be used for testing. Replace cap immediately and tightly after removing reagent strip. Unused strips that remain in the original capped container should be used within 3 months. Do not use reagent strips after the expiry date printed on the label.
Availability - Directly from QuicklyTest.
50 strips per container.
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In vitro diagnostic medical device |  |
Temperature limitation |
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Consult instructions for use |  |
Do not reuse |
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Manufacturer | QuicklyTest, York UK | |
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Authorized Representative in the European Community | ||
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This product fulfils the requirements of Directive 98/79/EC on in vitro diagnostic medical devices | ||