proposed life states that the main criticism of nanobes is that they appear too small to contain the biochemical machinery needed to sustain life. The review also states that there is no evidence that nanobes are organisms in themselves and not fragments of larger organisms. Tony Taylor was one of the authors of the original nanobe paper. He argues that the conspicuous lack of phosphorus in the X-ray spectroscopy data and the failure to find DNA using various DNA amplification techniques demonstrates that nanobes do not have any DNA or RNA. He also argues that they may have a completely different mechanism for heredity, which would account for many of their unusual chemical and physical properties. See also Mycoplasma—smallest known bacteria (300 nm) Nanoarchaeum—smallest known archaeum (400 nm) Nanobacteria—possible lifeforms smaller than bacteria (<200 nm) Pandoravirus—one of the largest known viruses (1000 nm) Parvovirus—smallest known viruses (18-28 nm) Pithovirus—largest known virus (1500 nm) Prion—smallest known infectious agent (≈10 nm) Protocell Ultramicrocells—possible dormant forms of larger cells (200 nm) References External links Color photo of a nanobe colony Definition of nanobe Introduction to nanobes Nanobe images and links Transcript of 7.30 Report interview of Philippa Uwins Size Limits of Very Small Microorganisms Proceedings of a Workshop organized by the National Academies of Sciences How Small Can Life Be? on NAI news. Microbiology Hypothetical life forms