[Question #13600] NAAT Urine Test – Procedural Question

9 days ago

I have three brief questions regarding my recent NAAT urine test on 27 of november 2025 for chlamydia and gonorrhea(male): My local clinic instructed that the sample tube should be inverted 5 times before adding the urine, presumably to mix the stabilizing fluid before adding urin. I forgot to do this and added the urine directly, and I became worried because the clinic could not answer whether this step affects the result. Does skipping this step have any impact on the accuracy or reliability of NAAT urine testing(for any NAAT test type)? Also, how reliable are modern NAAT urine tests for chlamydia and gonorrhea in terms of sensitivity and specificity? Are swap more reliable than urin?

9 days ago

Sorry – small correction: I did not invert the sample tube 5 times after adding the urine, as stated in the Roche cobas PCR instructions and by the local clinics guidelines. I did not invert at all. I just want to confirm that the sample is still fully valid with this mistake?

Edward W. Hook M.D.

9 days ago

Welcome back to the farm. I’ll go straight to your questions:

1. Waiting to invert the tube containing your urine until after urine is in the tube will not invalidate or negatively affect the accuracy of the test results.

2 and 3. Urine NAAT tests for gonorrhea and chlamydia, including the Roche test that you were tested with, are statistically equivalent to swab tests for detection of gonorrhea and chlamydia infections. Testing with an initial void urine test is now the preferred and recommended mechanism for testing. These are without a doubt, the most sensitive and specific tests for detection of gonorrhea and chlamydia available. Although the sensitivity and specificity of urine specimens is statistically equivalent to that of swab tests, swab tests also consistently are very slightly, but not significantly more sensitive for detection of infection.

In summary, you can have confidence in the results of your ear test for gonorrhea and chlamydia. EWH.

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9 days ago

Thx doc. You misunderstood my first question slightly : One clarification:

I forgot to invert the urine tube both before and after adding the urine. I capped it tightly but did not invert it 5 times before placing it in the drop box to the doctor. Does this affect the accuracy of a NAAT result, or is the test still fully valid? Best

Edward W. Hook M.D.

9 days ago

Thanks for the additional information. My answer is unchanged. You can have confidence in your test results. EWH---

9 days ago

So just to be clear - no shaking or inverting the tube at all does not effect the result? Can I trust in this?

Edward W. Hook M.D.

9 days ago

Sigh. As in your multiple prior posts, you are worrying entirely too much about the reliability of the testing that you undergo. Currently available tests are VERY forgiving. Your repetitive question is not going to get a different answer. Not shaking or inverting the test will not affect the result.

As you know, we provide up to 3 responses to questions, even those that repeat themselves. This thread is now complete and will be closed shortly. There should be no need to return. EWH

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