Urine Strips
Biochemistry

Urine Strips

The use of urine test strips is acknowledged as modern screening method in medical practice. With these non-invasive tests important information on the health status of the patient is rapidly obtained. The urine sample is easily drawn and can immediately be investigated with a test strip. Thus one obtains within minutes a result, which facilitates the decision for further diagnostic and therapeutic action. Only on pathological results for certain parameters, a subsequent, e.g. microscopic, examination of the urine is necessary. If the test strip result is without pathological finding and the patient is not clinically conspicuous, further time- and cost-intensive investigations, can often be avoided. This saves considerable costs for the healthcare system and spares the patient unnecessary examinations.

Description

The URYXXON® 500 is an automatic reader for URYXXON® Stick 10 urine test strips. With a capacity of 400 strips per hour, it is ideal for use in hospitals and practices. The “easy-to-use-features” allow hygienic operation with hardly any training. The URYXXON® 500 provides dependable urine status results to detect early stages of many diseases such as urinary tract infections, kidney diseases or diabetes. The device eliminates the subjectivity of visual strip evaluation and minimizes risks associated with manual result transcription. The URYXXON® 500 makes urine analysis quicker, easier and more reliable.

Major merits
  1. Glucose test for blood: The detection is based on the glucoseoxidase-peroxidase-chromogen reaction and oriented towards supervision of diabetics, or suspected diabetes, diabetics self supervision.
    (a) Test strip for Glycaemie V: The strip is meant for only visual evaluation, performed by comparison with the colour scale in the graduations 60, 120, 240 and 800 mg/dl.
    Test strip for Glycaemie C: The strip is meant for visual evaluation. The bicoloured test strips allow a semiquantitative determination of blood glucose in the range from 20 to 800 mg/dl. Due to the clear differentiation, test allows detection of a hypoglycemia as well as hyperglycemia.
  2. Urine test strips Microalbumine for albumine and creatinine: Urine test strip for test parameters albumine and creatinine ratio with quick results in about 60 seconds.
    Range – Albumine : 10 – 150 mg/L ; Creatinine: 10 – 300 mg/dL
    Classification in normal, abnormal (microalbuminurie) and highly abnormal (macroalbuminurie / proteinurie)
    Principle – Albumine test is based on the principle of “protein error” of indicators.
    Creatinine – The detection is based on the reaction of creatinine with dinitrobenzoic acid.
  3. Adulteration test stick:Medi-Test adulteration stick reliably detects unusual levels of creatinine, nitrite, glutaraldehyde, pH, specific gravity and oxidants generally connected with classical and commercial adulterants. The adulterants include commonly available substances like water, bleach, vinegar etc.Type – Urine dipstick
    Presentation – Tube of 50 strips
    Parameters – Creatinine, Nitrite, Glutaraldehyde, pH, Specific Gravity and Oxidisers
    Reference(pack of 50) – 93019
    FDA 510(k) – K991927
    Complexity – Waived
Clinical Applications
  1. Glucose: The test for glucose is especially suitable for the detection of diabetes mellitus and for supervising and self-supervising of diabetes.
  2. Ketones: The two conditions associated with an elevated concentration of ketones in urine are diabetes mellitus and starvation. This ketosis is an important finding because untreated it can lead to acidosis and consequently coma or even death.
  3. Ascorbic acid: Ascorbic acid (vitamin C) is neither a pathological nor a normal urine constituent. The result of this test itself has only very limited diagnostic significance. However, ascorbic acid in high concentrations may interfere with the measurement of other chemical tests, e.g. blood or glucose.
  4. Protein: The presence and the concentration of protein in urine is probably the most important single finding in the detection of renal diseases
  5. Blood: Blood in urine is an important finding and may be caused by bleeding at any point in the urinary tract. It is a sensitive early detector of renal disease that should not be missed!
  6. Leukocytes: An increased excretion of leukocytes in urine is an important symptom for infectious diseases of the kidneys and /or the urinary tract.
  7. Nitrite: Tests for nitrite in urine are frequently used as a rapid method for detecting urinary tract infections.
  8. Specific Gravity (Density): The specific gravity is used to check the function of the kidneys and to obtain information about the patient’s state of hydration. In general, the specific gravity is a measure for the concentration of the urine.
  9. pH: The urine pH is of significance mainly in combination with other parameters. In some cases it is used to control the dose of pH-changing drugs.
  10. Bilirubin: Tests for urinary Bilirubin are important in detecting liver diseases. In combination with the result for Urobilinogen it helps to distinguish between different types of jaundice.
  11. Urobilinogen: Elevated concentrations of Urobilinogen in urine (>1 mg/dl) may be among the first signs of liver disease and disfunction.
  12. Glucose test for blood by visual evaluation:
    (i) Strips Glycaemie V by comparison with colour scale.
    (ii) Strips Glycaemie C, bicoloured allowing semi quantitative determination from 20 to 800 mg/dl.
  13. Microalbumine urine test strips, for microalbumine and creatinine.
  14. Adulteration test stick: Test stick for detection of intentional tampering with urine sample to avoid detection of illicit drug use, as successful adulteration produces false negative drug test.

Frequently Asked Questions
General
What is the sensitivity for protein detection?

The strips can detect protein from 30mg/dl and is more sensitive than most other strips available in the market.

Does your system indicate trace proteins?

No, Macherey Nagel system due to practical aspects, does not indicate trace proteins. It will be relevant to note that the micro-albuminuria can be confirmed by only special test. The semi quantitative urine strip method is not suited for this purpose. Hence technically, it would not be correct and hence trace protein is not available with Macherey.

Is there a specific reason for higher false positivity with the bilirubin results?

This is very likely due to the interference from drugs and is true of all strips and not confined to Macherey.

What are the specific drugs which affect the result of bilirubin?

It will be very difficult to list, since there is no document or data available about the drugs and their nature of interference with Macherey Nagel strips for bilirubin. Even if medication is known, it is not possible to distinguish between a false and a true positive, when one gets positive reading. So the only solution to get the patient history to rule out interference.

Are the results affected by Vitamin C?

10 parameter strips from Macherey have the best available protection against influences against Vitamin C and even at concentrations of 40 miligrams/dl of Vitamin C in the sample, results are accurate and without interference. Most test strips in market show the incorrect results at much lower Vitamin C concentration. With most strips often false negative readings are got, even due to small concentration of Vitamin C. Masking early stages of serious diseases is unlikely with Macherey and Nagel strips and so safer and better!

Is the sensitivity with Macherey Nagel strips adequate say for protein?

In the case of protein determinations, according to the literature (Urinalysis and Body Fluids), excretions of up to 1 g/day are regarded as non pathological. The normal urine volume/day is approx 1 to1.5L / day and it should not exceed 2.5 L/day. Even with 2.5 L/day the concentration would be 40 mg/dl or in other words well above the generally accepted detection limit of the protein test (30 mg/dl). So the sensitivity with Macherey and Nagel is quite good and adequate for the screening purpose!

Why the microalbuminuria is not offered as a screening parameter in M & N strip?

For patients with diabetes mellitus, a test on microalbuminuria is indicated. Such a test helps to predict the development of renal complications. For a safe diagnostic of microalbuminuria two things are essential:

  • One needs a test with a detection limit of around 2 mg/dl and there is no 10 parameter strip on the market that provides this.
  • One should have a creatinine test to calculate the albumin-creatinine ratio. Only in relation to the creatinine value the microalbumin value can be used for a final diagnosis. Again, no 10 parameter test provides this.
What is the advantage of glucose detection of 50 mg/dl rather than 100 mg/dl?

The URYXXON Stick has the highest available sensitivity for Glucose in urine. Even 50 mg/dl Glucose can be safely detected. That means URYXXON Stick 10 is twice as sensitive compared to most competitors’ strips that report only 100 mg/dl. So using the URYXXON Stick provides for best safety for the patients. Low positives are reported and further diagnostic can be initialised. Treatment of patients can start earlier with better chances to prevent long-term damages. The Glucose test of the URYXXON System provides the best available safety to detect diabetics.

Is there any specific reason for bilirubin results indication in orange colour?

Macherey Nagel Bilirubin pad in the stick let us say indicates an orange colour. Often urobilinogen and bilirubin indicate positivity and when checked manually in Elrich method, the results may be negative. The orange colour with M&N strips indicates an interference. The Uryxxon system reports this test as positive because a real positive might “hide” under this colour. As a screening system, the URYXXON should not give false negative results, while false positives are acceptable to some extent by comparison. The approach and the procedure adapted by Macherey, ensure that no patient is harmed. False positives are immediately recognised in the analysis and the lab does not overlook a real positive.

In the case of semi quantitative test strips is there any real benefit of higher level sensitivity?

Yes, there is a significant reason and all the more higher sensitivity of various parameters is very meaningful especially for screening for very early detection as M&N strips do not mask disease with poor sensitivity.