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Testing with uSense™ is Quick and Easy

Watch this quick video for instructions on how to use uSense™ for Lead

Testing with uSense™ is Quick and Easy

By following these simple steps, you can test your water for lead.

Step 1 — Sample Collection

A)  Proceed

Please refer to “Drinking Water Provider Instructions” included with this kit for the sample-collection protocol to follow.

Providers may vary on sample collection requirements.

B)  Reference

Once you have successfully collected your sample, grab your Test Kit and move to Step #2, Sample Testing.

Step 2 — Sample Testing

A)  Prepare

Note: Only proceed to this step once water sample has been collected from Step 1.

Before getting started, read instructions to ensure proper kit performance.
Remove the 2 pouches from the box. They are Labeled Test Tube and Test Strip. Open and empty Test Tube Pouch.

With bottom of Test Tube, push through perforations on Test Tube Holder on Box.

Proceed to 2B Pipette.

B)  Pipette

Note: This is the most critical step to ensure accurate test performance.

Uncap the Test Tube, keeping cap for later.

Taking the Pipette provided, squeeze the TOP bulb to compress the bulb.
Submerge the Pipette into Sample Water.

Release the pressure on the TOP bulb to fill the pipette with your Sample Water.

A very small amount of Sample Water will flow into the lower bulb, as well as the leg of the Pipette. This is normal.

Proceed to 2C Rehydrate.

C)  Rehydrate

Position your filled Pipette inside the lip/ threaded collar of the Test Tube.

Squeeze the TOP bulb ONE TIME to deposit your Sample Water into the Test Tube. Dispose of Pipette.

Proceed to 2D Mix & Process.

D)  Mix & Process

Recap the Test Tube and remove it from the Test Holder.

Flick the bottom of the tube firmly 3 times to mix. Return tube to the Test Tube Holder.

Allow the Test Tube to sit, undisturbed, for 15 minutes.

Proceed to Step 2E Dip Test Strip.

Proceed to 2E Dip Test Strip.

E)  Dip Test Strip

Note: False results may occur if timing instructions are not followed.

After 15 minutes, remove the cap from the Test Tube.

Unpack the Test Strip Pouch, taking care to touch only the top, covered section of the Test Strip labeled “Handle Here.”

Deposit the Test Strip into the Test Tube, arrows pointed DOWN.

Allow the Test Strip to sit, undisturbed, for 10 minutes to allow test bands to form.

Proceed to #3 Read Results.

Step 3 — Read Results

After 10 minutes, remove the Test Strip from the Test Tube.

Compare your Test Strip with the examples below to determine whether ≥ 5 ppb Lead is Detected (Positive) or if Lead is Not Detected (Negative). An Invalid Test occurs if no band forms.

A)  Compare Results

Lead Not Detected (Negative)

No visual indicator of a second line; only the right “control” is visible.
No lead ≥ 5 ppb is detected.

Lead Detected (Positive)

Visual indicator of a clear, second line to the left of the ”control” line.
≥ 5 ppb lead is detected in your sample. ​

B)  Report Results

Scan this QR code for instructions on reporting your results. Providing your results in a timely manner helps your community prioritize remediation efforts.

You can also report results by visioning:

Note: Report results within 5 minutes of test completion.

Was lead detected?

For the requested photo(s), please use the instruction pamphlet and the gray box as a background to capture an accurate picture.

All test materials can be safely disposed of in the garbage.

uSense™ for Lead Frequently Asked Questions

Here you can find some of the questions we are asked most frequently, and perhaps answer an inquiry.

Why am I receiving this lead-in-water test?

Your drinking water provider has partnered with Stemloop to deliver this uSense for Lead test to your residence. As part of EPA regulations, your provider required to make an inventory of residences impacted by lead piping. Water testing with uSense helps the provider complete this inventory and enables the provider to proactively plan for removal of lead piping.

If I test positive for ≥5 ppb lead, what should I do next?

When submitting your results to your drinking water provider through the QR code, you have the option to opt-in to a contact from your drinking water provider. Your provider can point you to your local resources to protect yourself and your family from lead contamination. Common methods of remediation include point-of-use filtration, reverse-osmosis filtration, or lead-service-line removal.

Why does incubation timing matter so much for the test? What should I do if I make a mistake in timing my test?

Incubation timing is crucial to a properly-run uSense test; under or over-incubating samples can lead to false negatives or false positives. The reaction timing is specifically tuned to identify ≥5 ppb lead. If you make a mistake in timing your test, we recommend reaching out to your drinking water system for a replacement test to ensure the most accurate results possible.

What do I do if my test kit is missing a component?

We have rigorous quality standards for uSense for Lead. Most-often, missing components can be found in their associated pouch. That said, mistakes can occur, either at Stemloop HQ or one of our vendor-partners. If you’re missing a component, please utilize the contact form at the bottom of this page.

What are the health impacts of lead in my drinking water?

Lead is a neurotoxic, and there is no safe level of lead in drinking water. For more information, check out the EPA’s Basic Information on Lead in Drinking Water, found here:

Can I order more tests for the rest of my home?

At this time, uSense for Lead is only available through your drinking water provider. Lead in water is a complex problem: while uSense helps identify sources of that problem, it is not able to remove the sources of lead from your home. By partnering with drinking water systems and filtration providers, uSense provides actionable information to deliver safer sips across the United States.

What is the difference between soluble and total lead?

Soluble lead is lead that is dissolved in water. It is odorless, colorless, and visually imperceptible to the human eye. Particulate lead is non-soluble, showing up in a glass of water as tiny metal particulates, sometimes visible to the human eye. For a test to measure “Total Lead,” samples need to be acidified and heated to break down particulate lead. This sample preparation step is not feasible in an at-home setting, so uSense is rate to measure soluble lead only (Note: uSense can be run with a ___% nitric acid digestion to capture total lead when run by trained operator).

How accurate are uSense for Lead tests?

uSense for Lead’s performance is tested under strict laboratory requirements. The test is 95% accurate when run per the instructions. There *are however, some known interferences that can impact test accuracy. Drinking water with a high rate of zinc (≥250 ppb) can result in a high rate of false positive tests; drinking water providers are discouraged from deploying uSense in areas with high zinc concentration.

uSense for Lead is a biosensor, meaning it takes nature’s innate sensing mechanisms and repurposes them. Through a combination of DNA, RNA, and Proteins, the test reacts with drinking water, genetically sensing the presence of soluble lead and visually reporting on the test strip. This is similar to how a Covid-19 or Pregnancy Test operate. Interested in learning more? Check out

I’m having difficulty running my test or reporting my results. Who can I contact for help?

We’re sorry to hear you’re having difficulty with uSense for Lead. We encourage you to watch the instructional video above and read through these FAQs. Should the problem persist, please utilize the contact form at the bottom of this page.

© Copyright 2024 Stemloop Inc.

All rights reserved


Contact us for more information.

Contact Form

© Copyright 2024 Stemloop Inc.

All rights reserved


Contact us for more information.

Contact Form

© Copyright Stemloop
All rights reserved