"Blood from a patient is drawn through microscopic channels where it then meets chemicals that react with HIV and syphilis antibodies to produce a color change. This can then be picked up by a set of photocells in the dongle, and the results are then sent to an app on the attached smartphone or computer."
Huh...I'd read the earlier article and didn't remember seeing that explanation. I didn't read this variant of the article, as I assumed the one I saw earlier was the more authoritative source, but, perhaps this is just a better article.
Quote from the article:
"Blood from a patient is drawn through microscopic channels where it then meets chemicals that react with HIV and syphilis antibodies to produce a color change. This can then be picked up by a set of photocells in the dongle, and the results are then sent to an app on the attached smartphone or computer."