How to Read Urine Test Strips Correctly: Colour Chart, Timing & Common Errors
Dr Pramod kumar
How Do You Read a Urine Test Strip Correctly?
Urine reagent strips are designed to provide quick screening information from a urine specimen, but accurate interpretation depends on more than simply dipping the strip into urine and looking at the colours.
Correct urine-strip testing requires attention to:
- Specimen collection
- Strip storage and handling
- Correct immersion
- Removal of excess urine
- Parameter-specific reading times
- Correct colour-chart comparison
- Appropriate lighting
- Product-specific Instructions for Use
This guide explains the general workflow for visual urine reagent-strip testing and the most common mistakes that can affect interpretation.
For a broader introduction to urine chemistry testing, read our Urinalysis & Urine Test Strips Complete Guide.
Step 1: Collect a Suitable Urine Specimen
Reliable reagent-strip testing begins with proper specimen collection.
Use a clean, suitable urine specimen container appropriate for the intended test.
A general urine collection workflow may include:
- Use an appropriate specimen container.
- Collect the urine sample according to the healthcare professional or laboratory instructions.
- Avoid touching the inside of the container or lid.
- Close the container securely after collection.
- Label professional laboratory specimens according to local procedures.
- Test or transport the sample within the recommended time and storage conditions.
View Urine Specimen Container →
Why a Fresh Urine Sample Is Important
Urine chemistry can change after collection.
If a specimen is left standing for too long or stored incorrectly, several characteristics may change and potentially affect reagent-strip interpretation.
Whenever possible, use a fresh urine specimen and follow the product or laboratory instructions for specimen stability and storage.
Specialized investigations such as urine culture, timed urine collection or other laboratory tests may require different collection and handling procedures.
Step 2: Check the Urine Test Strip Before Use
Before removing a strip, check:
- The correct product has been selected.
- The required parameters are present on the strip.
- The expiry date has not passed.
- The reagent pads do not appear damaged or abnormally discoloured.
- The strip container has been stored according to the manufacturer's instructions.
Do not use a strip if its reagent areas appear damaged before testing.
Step 3: Remove One Strip and Close the Container
Remove only one reagent strip at a time.
Avoid touching the chemically treated reagent pads with your fingers.
Immediately close the strip container after removing the strip.
Leaving the container open can expose unused strips to humidity and environmental moisture, which may affect reagent stability.
Step 4: Immerse the Reagent Areas in the Urine Sample
Immerse the reagent areas according to the Instructions for Use supplied with the specific strip.
The pads should be adequately exposed to the specimen, but the exact dipping time varies between products.
Do not assume that all urine reagent strips use the same immersion time.
Step 5: Remove Excess Urine
After immersion, remove the strip according to the product instructions.
Excess urine may need to be removed carefully so that liquid from one reagent pad does not run onto another pad and interfere with neighbouring reactions.
The exact technique varies by product and may include:
- Drawing the strip edge against the specimen container
- Blotting the strip edge where instructed
- Holding the strip in the specified orientation
Always follow the method described in the product IFU.
Step 6: Start Timing Immediately
Timing is one of the most important parts of urine reagent-strip interpretation.
Each reagent pad undergoes a chemical reaction after exposure to urine. The manufacturer's colour chart is designed to be interpreted at specific development times.
Do not simply dip the strip, wait an arbitrary amount of time and then read all parameters together.
Why Different Urine Test Parameters Have Different Reading Times
Different reagent chemistries develop at different rates.
For example, the reagent systems for parameters such as:
- Glucose
- Protein
- Ketones
- Blood
- Nitrite
- Leukocytes
may not all reach their intended interpretation point at the same time.
Always follow the parameter-specific reading times stated in the colour chart or Instructions for Use supplied with the product.
What Happens If You Read a Urine Strip Too Early?
If a reagent pad is read too early, its chemical reaction may not have fully developed.
This may result in a colour that does not yet correspond accurately to the intended reference scale.
What Happens If You Read a Urine Strip Too Late?
Reading a reagent area significantly later than specified may also lead to misleading interpretation because the colour reaction may continue changing after the recommended reading time.
The correct result should therefore be determined at the manufacturer's specified interpretation time.
Step 7: Compare Each Pad with the Correct Colour Chart
For visual testing, compare each reagent pad with the corresponding row on the colour reference chart supplied with the product.
Match:
- Glucose pad to the glucose scale
- Protein pad to the protein scale
- Ketone pad to the ketone scale
- Leukocyte pad to the leukocyte scale
- And so on for each parameter present
Do not compare a pad against another parameter's colour scale.
Never Use a Colour Chart from Another Brand
Urine-strip colour charts are product-specific.
Different manufacturers may use different reagent formulations, colour ranges and interpretation scales.
Do not substitute:
- A colour chart from another brand
- A chart from another strip configuration
- An image found online
- A chart from an older or different product pack
Use only the chart supplied for the exact reagent-strip product being tested.
Use Suitable Lighting
Visual colour interpretation should be performed under suitable neutral lighting.
Avoid:
- Strongly coloured lighting
- Very dim lighting
- Reflections that make reagent colours difficult to distinguish
- Direct intense glare
Lighting conditions can influence how colours are perceived.
How to Hold the Strip While Reading
The strip should be held or positioned according to the manufacturer's instructions.
Avoid allowing liquid from one reagent area to flow onto neighbouring pads, as this may affect colour reactions.
Some products specify a particular orientation during development and interpretation.
Understanding the Urine Test Strip Colour Chart
Most urine reagent-strip charts provide a series of reference colours corresponding to qualitative or semi-quantitative result ranges.
Depending on the parameter, results may be expressed using:
- Negative
- Trace
- Positive categories
- Approximate concentration ranges
- pH values
- Specific gravity values
The result format depends on the particular reagent-strip system.
What Do LEU, NIT, URO, PRO, pH, BLO, SG, KET, BIL and GLU Mean?
A common 10-parameter urine test strip includes:
| Code | Parameter |
|---|---|
| LEU | Leukocytes |
| NIT | Nitrite |
| URO | Urobilinogen |
| PRO | Protein |
| pH | Acidity / Alkalinity |
| BLO | Blood |
| SG | Specific Gravity |
| KET | Ketones |
| BIL | Bilirubin |
| GLU | Glucose |
For detailed explanations of each parameter, read:
10 Urine Test Strip Parameters Explained: LEU, NIT, URO, PRO, pH, BLO, SG, KET, BIL & GLU →
Common Mistakes When Using Urine Test Strips
1. Using an Old Urine Specimen
Specimen chemistry may change after collection, particularly when storage conditions are inappropriate.
2. Using an Unsuitable Collection Container
Residues, detergents or contaminants can potentially interfere with testing.
3. Touching the Reagent Pads
Finger contact may contaminate or alter the chemically treated areas.
4. Leaving the Strip Container Open
Humidity can affect unused reagent strips.
5. Over-Immersing the Strip
Immersion procedures are product-specific. Longer dipping is not necessarily better.
6. Not Removing Excess Urine Correctly
Excess liquid may cause reagent chemicals or urine to migrate between neighbouring pads.
7. Reading All Parameters at the Same Time
Different reagent pads may have different interpretation times.
8. Using the Wrong Colour Chart
Charts should never be interchanged between products.
9. Reading in Poor Lighting
Colour perception can be affected by unsuitable lighting.
10. Using Expired Strips
Expired strips should not be used.
Can Urine Test Strips Be Reused?
No.
Urine reagent strips are designed for single use only.
Once the reagent areas have contacted the specimen and reacted, the strip cannot be reused for another sample.
Can You Dip the Same Strip Twice?
Unless the manufacturer's specific instructions state otherwise, the strip should be used according to the prescribed single testing procedure.
Repeated dipping after the reagent reaction has begun may interfere with test development.
Focused Strips vs 10-Parameter Strips
Not every urine test requires a 10-parameter strip.
| Testing Requirement | Suggested Strip |
|---|---|
| Glucose only | 1-parameter glucose strip |
| Glucose + Protein | 2-parameter GLU + PRO strip |
| Glucose + Ketones | 2-parameter GLU + KET strip |
| Broader urine chemistry screening | 10-parameter strip |
For help choosing:
Read: Urine Test Strips Comparison – Glucose + Protein vs Glucose + Ketone vs 10 Parameter →
Microsidd Urine Test Strip Options
Glucose + Protein
For focused GLU + PRO screening:
Microsidd Glucose + Protein Urine Test Strips →
Glucose + Ketones
For focused GLU + KET screening:
Microsidd Glucose + Ketone Urine Test Strips →
10-Parameter Urinalysis
For broader routine urine chemistry screening:
Microsidd URS10T 10-Parameter Urine Test Strips →
Mission Urinalysis Strip Options
- Mission 1G – Glucose
- Mission 2GP – Glucose + Protein
- Mission 2GK – Glucose + Ketones
- Mission 10U – Multi-Parameter Urinalysis
Visual Reading vs Urine Analyzer Reading
Visual interpretation works well for many urine reagent-strip workflows, but laboratories processing larger numbers of specimens may use a compatible urine chemistry analyzer.
| Visual Strip Reading | Analyzer Reading |
|---|---|
| Operator visually compares colours | Optical system reads reagent-pad reflectance |
| Suitable for lower-volume testing | Useful for repeated professional workflows |
| Results generally recorded manually | Results may be stored, printed or transferred |
| Lighting and operator perception can affect comparison | Helps standardize compatible strip interpretation |
Microsidd supplies professional urine chemistry analyzers including:
Important: Analyzer compatibility must be confirmed for the exact strip configuration. Do not assume that every strip from the same brand works with every analyzer.
Should You Use Visual Reading or an Analyzer?
Visual reading may be appropriate when:
- Testing volume is relatively low.
- A compatible visual strip is being used.
- Result storage and connectivity are not required.
An analyzer may be preferable when:
- Many samples are processed each day.
- Several operators perform testing.
- More standardized strip interpretation is desired.
- Result storage or printing is needed.
- Barcode or LIS workflows are required.
How to Store Urine Test Strips
Proper storage is essential because reagent pads are sensitive to environmental exposure.
- Keep strips in the original container.
- Keep the container tightly closed.
- Protect from excessive moisture.
- Protect from direct sunlight and excessive heat.
- Do not touch reagent areas.
- Do not transfer strips into another container.
- Follow the stated storage temperature.
- Observe opened-container stability where applicable.
- Do not use beyond the stated expiry date.
Can an Abnormal Urine Strip Result Diagnose a Disease?
No.
Urine reagent strips are primarily screening and monitoring tools.
An abnormal result may need to be interpreted together with:
- Symptoms
- Medical history
- Medications
- Diet
- Hydration
- Other urine parameters
- Blood tests
- Microscopy
- Urine culture
- Clinical examination
Persistent or clinically significant abnormalities may require additional investigation.
Explore the Microsidd Urine Chemistry Knowledge Hub
This article forms part of Microsidd's Urine Chemistry Knowledge Hub.
Continue learning:
- Urinalysis & Urine Test Strips Complete Guide
- 10 Urine Test Strip Parameters Explained
- Urine Test Strips Comparison
Shop the Complete Urine Chemistry Collection →
Frequently Asked Questions
How long should you dip a urine test strip?
The correct immersion time depends on the product. Always follow the Instructions for Use supplied with the exact strip rather than applying one universal dipping time.
How long should you wait before reading a urine test strip?
Each parameter may have its own specified reading time. Follow the product-specific colour chart and IFU.
Can I read all urine-strip parameters at the same time?
Not necessarily. Different reagent pads may require different development times.
What happens if I read the strip too late?
The reagent colour may continue changing after the recommended interpretation time, potentially affecting result interpretation.
Can I use a urine-strip colour chart from another brand?
No. Use only the reference chart supplied with the exact product because reagent formulations and colour scales may differ.
Can I use an online urine-strip colour chart?
An online image should not replace the product-specific colour chart supplied by the manufacturer.
Can urine test strips be reused?
No. They are intended for single use only.
Does more dipping time improve accuracy?
No. The strip should be immersed according to the manufacturer's specified procedure.
Should urine be fresh for dipstick testing?
Fresh urine is generally preferred for routine reagent-strip testing because urine chemistry may change during storage. Follow the specimen-handling instructions for the intended test.
Why should I close the strip container immediately?
Reagent strips are sensitive to moisture and environmental exposure. Keeping the container tightly closed helps protect unused strips.
Why should I avoid touching the reagent pads?
Touching the chemically treated areas can introduce contamination or substances that may interfere with their reaction.
Do I need a urine analyzer?
No analyzer is required for strips specifically designed for visual interpretation. Laboratories with higher testing volumes may prefer compatible analyzer-based reading.
Which container should I use for urine testing?
Use a clean, suitable specimen container appropriate for the test.
View Urine Specimen Container →
Medical Information Notice
This article is provided for general educational and product-use information and is not a substitute for medical advice, diagnosis or treatment.
Urine reagent-strip results may be affected by specimen collection, storage, timing, medication, diet, hydration, testing technique and other physiological or clinical factors.
An abnormal urine-strip result should not automatically be interpreted as a specific disease or condition.
Unexpected, persistent or clinically significant findings should be evaluated by an appropriately qualified healthcare professional and confirmed with additional laboratory or clinical investigations where necessary.
Do not start, stop or modify medication, insulin, diet or other medical treatment solely on the basis of a urine reagent-strip result.
Always follow the Instructions for Use supplied with the exact urine reagent strip being used.