Faint red spreading after 15 minutes
Hi, I found there was some faint red spreading after 15 minutes from the bottom of my strip in my testing after I laid down my sample. The faint red started to appear at right corner of my strip and spread all over the trip and then disappeared gradually. And
I could see a clear control line and there was no testing line. Is it a normal negative result? Thank you.
Gary Carpenter, BioSure (UK) Limited
Work on 26th January 2018
Hi DT,
Yes, this is normal. You should only read the test at around the 15 minute mark. The background can discolour over time. The first result you read should be the one you rely on.
I hope that this helps.
Kind regards
Gary
DT
Used on 26th January 2018
And the background on the strip got a little bit pink when the test was finished, is that normal? Thank you.
Gary Carpenter, BioSure (UK) Limited
Work on 26th January 2018
Hi DT
Thanks for getting in touch.
Yes, this is completely normal. The chemicals in the test, the buffer solution and the blood sample gradually move up the strip. As these chemicals pass along the strip, depending on what is in the sample, they can can be "captured" by other chemicals applied to the strip during manufacture. If there are no antibodies to HIV the chemicals move over the test line and are not captured there, so no line is visible. If you have applied enough human blood to the test as the chemical mixture moves over the control line, the control line will be triggered and will become visible.
I hope that this helps to answer your question.
Kind regards
Gary Carpenter
BioSure (UK) Limited
