In the case of Oxford Nanopore's technology, the DNA molecule is fed through the hole one base at a time by a second protein, an enzyme called an exonuclease.
"We are getting a look at the everyday life of a supermassive black hole like never before, " said Frederick Baganoff of the Massachusetts Institute of Technology (MIT), US, who presented the new data on behalf of an international team at the American Astronomical Society meeting in Seattle.