A team of researchers at Iowa State University, Ames, has devised a way to spot DNA from a single particle of human papilloma virus (HPV), which can cause cervical cancer.
The researchers apply a sample from a cervical smear to a slide covered with copies of a DNA sequence that is complementary to part of the HPV DNA. They say that HPV DNA in the sample then sticks to the slide.
Thereafter, the researchers add copies of a second sequence that sticks to HPV and is bound to a fluorescent molecule, which shows up each virus particle as a spot of light.
It might also be adapted to detect flu, reports New Scientist magazine.