undetectable

During those same two decades, neurogenesis slows to the point where immature brain cells became nearly undetectable.

Expectant moms like this merit additional scrutiny because it’s unclear whether they have undetectable cancer or are healthy, says Macville, who’s also encountered them.

Researchers were able to uncover traces of natural selection -- signs of genetic adaptation to environmental pressures -- that are undetectable in the DNA of modern Europeans.

My viral load has been undetectable for years, meaning I cannot spread the virus to others.

When the bite of an Anopheles mosquito introduces Plasmodium into the human bloodstream, the parasites travel to the liver, where they lurk undetectably and mature for a period ranging from weeks to a year.