[Question #6850] Testing Guidance

13 months ago
Hi there,

We’re in lockdown in the UK due to the Covid19 situation.

I ordered a home test kit from a reputable private clinic which tests for chlamydia, ghonorreah, M. genitalium and Trich. 

The test kit involved urinating into a small box containing a plastic/cellophane inner which I then had to pour into a sample tube, also provided. 

The box held an awful lot of urine so after pouring my urine from the container to the top of the tube (25ml-30ml size tube) there was still a lot of urine left in the box container which I disposed of.

Full up, the box container held 150ml of liquid (I checked with water and measured the volume) so I guess my initial void was between 100ml-150ml.

My question is whether transferring 25ml-30ml of urine from a 100-150ml void would impact the accuracy of the test as would it not dilute things? 

Thanks for your advice on this. 




Edward W. Hook M.D.
Edward W. Hook M.D.
13 months ago
Welcome to our forum and thanks for your question. Current nucleic acid amplification tests for a diagnosis of these STI‘s is amongst the most sensitive of all laboratory tests. These tests are able to detect very few organisms in initial void urine tests.  The fact that you completely filled your collection container before transferring a smaller amount of it to the processing tube will not affect results. When your test results returnYou will be able to have confidence in them.

I hope that this information is helpful to you. If any part of this is unclear please feel free to use your up to two follow-up questions for clarification. Take care. EWH
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12 months ago
Thank you Doctor and sorry for the late follow up. My results came back negative.

So just to be sure, given my initial urine void could have been up to 150ml volume,
this wouldnt have diluted the sample i transferred to the sample tube to the detriment of the accuracy of the results?

Just want to be clear that you understand my initial void was high and up to 150ml volume range. 

Thanks again Doctor 


Edward W. Hook M.D.
Edward W. Hook M.D.
12 months ago
Glad to hear that your results were negative- I would urge you to believe them.  That your urine specimen was about 150 ml will not negatively impact test performance or accuracy.  EWH
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