The principle behind the the ZstatFlu™ test is straightforward.  Influenza neuraminidase from the patient specimen cleaves the proprietary ZstatFlu™ substrate to release a blue precipitate that accumulates on the collection device membrane.   The criterion for a positive test result is “any shade of blue” in the collection device.   A positive test can be very lightly blue, or so dark that it appears nearly black.  Most clinical positives are a light to medium shade of blue.

The animation below simulates the development of a positive test result in the collection device as the test solution drains.  Color development in the square region is meant to represent the focusing area of the collection device.  The length of this animation is 12 seconds, or about 1/10th the drain time of a typical ZstatFlu™ test.

Due to the variable display characteristics of the computer monitor it is impossible to accurately illustrate the coloring of a very weak ZstatFlu™ positive test result (a shade of blue that appears faint on your screen may be imperceptible on a different monitor).  With this in mind, the images shown in ZstatFlu™ visual database are intended as a guide, and not as a definitive reference standard.   The lightest shade of blue shown in the images below is not necessarily the minimum blue color possible with a test positive.  Remember: If you see any shade of blue in the collection device then the test is positive!

The color gradient below covers the spectrum of blue shading observed in the majority of positive ZstatFlu™ test results.  This gradient may assist you in determining whether your test is positive or negative.

Examples of Actual ZstatFlu™ Positive Test Results

A negative ZstatFlu™ test is usually, but not always, white or off-white.  Negative test results may also be beige, yellow-brown, olive, gray, or any combination of these colors.  Other “test-negative” colors are also possible.  Since the patient specimen is drawn from the throat, the presence of mucus, blood, colored food or beverage, or medicinal substances in the mouth or throat can collect on the swab and potentially transfer through the test process.

We have included images from actual ZstatFlu™ negative tests below.  For each test result shown, no hint of blue could be discerned in the focusing area of the collection device, although other colors were present.  We have also included two color gradients that illustrate the range of colors you might see in a ZstatFlu™ negative test.  Again, remember that most ZstatFlu™ negative tests are simply white or off-white.

Examples of Actual ZstatFlu™ Negative Test Results

If you have compared your test sample with the positive and negative controls and consulted this database and still need assistance, please contact ZymeTx Customer Support directly.

ZymeTx Customer Support
Phone: 1-888-817-1314
Fax:    1-877-854-4187
email:  support@zymetx.com