The Nanoarchaeota were proposed as the fourth archaeal sub-division in 2002, and the only fully characterized nanoarchaeon was found to exist in a symbiotic association with the crenarchaeote, Ignicoccus sp. This nanoarchaeote, named Nanoarchaeum equitans could not be detected with &ldquo / universal&rdquo / archaeal 16S PCR primers and could only be amplified using specifically designed primers. In order to identify and access a wide diversity of archaeal phylotypes a new set of &ldquo / universal&rdquo / archaeal primers A571F (5&rsquo / -GCY TAA AGS RIC CGT AGC-3&rsquo / ) and UA1204R (5&rsquo / -TTM GGG GCA TRC IKA CCT-3&rsquo / ) was designed, that could amplify the 16S rRNA genes of all four archaeal sub-divisions. Using these primers community DNA was amplified from Chinese and New Zealand hydrothermal systems.

The Nanoarchaeota were proposed as the fourth archaeal sub-division in 2002, and the only fully characterized nanoarchaeon was found to exist in a symbiotic association with the crenarchaeote, Ignicoccus sp. This nanoarchaeote, named Nanoarchaeum equitans could not be detected with &ldquo / universal&rdquo / archaeal 16S PCR primers and could only be amplified using specifically designed primers. In order to identify and access a wide diversity of archaeal phylotypes a new set of &ldquo / universal&rdquo / archaeal primers A571F (5&rsquo / -GCY TAA AGS RIC CGT AGC-3&rsquo / ) and UA1204R (5&rsquo / -TTM GGG GCA TRC IKA CCT-3&rsquo / ) was designed, that could amplify the 16S rRNA genes of all four archaeal sub-divisions. Using these primers community DNA was amplified from Chinese and New Zealand hydrothermal systems.