Mouse cloned from one blood drop
27 June 2013 Last updated at 18:03 BST
Scientists in Japan have cloned a mouse from a single drop of blood, according to a report in the journal Biology of Reproduction.
The team at the Riken BioResource Center used circulating blood cells from a donor mouse's tail to produce the clone, a female mouse with a normal lifespan.
The researchers' aim was to find an easily available source of donor cells to clone scientifically valuable strains of laboratory mice.
Christopher Mason, Professor of Regenerative Medicine Bio-processing at University College of London, told the BBC successfully cloning mice "had been a challenge."