_:vb6940208 "The fragments shrank by increments of about three kilodaltons (a measure of molecular weight)."@en . _:vb6940207 "A unit of measurement. [from 14th c.]"@en . _:vb6940208 "1993, Scientific American, February 33.3:"@en . . _:vb6940207 . "2.4" . _:vb6940208 .