[2] In particular, given its association with sites of active anaerobic oxidation of methane (AOM), it is considered a biomarker of methanotrophic archaea.

[5] Biphytane is produced by the chemical cleavage of the ether bonds within isoprenoid GDGT (GDGT-0).

[6] While early studies had considered GDGTs (and hence biphytane) to be biomarkers of extremophilic archaea, both indirect and direct evidence of GDGT originating from archaea of mesophilic marine environments or lacustrine environments with non-extreme pH and salinity have been available since the late 1970s.

The obtained saturated or derivatized hydrocarbons can subsequently be separated and measured using standard gas chromatography-mass spectrometry (GC-MS) procedures.

[6] Alternatively, direct analysis of GDGT can be done with liquid chromatography but, when further structural characterization is required, MS fragments characteristic of biphytane can be obtained via high-performance liquid chromatography linked to tandem mass spectrometry (HPLC-MS/MS).

[13] In 2006, Ventura et al. measured solvent-extractable hydrocarbons with GC-MS from metasedimentary rocks sampled from the Tisdale and Porcupine Assemblage (2,707 to 2685 Ma) near Timmins, ON, Canada.

[14] Because post-Archaean deposition of the compounds could be ruled out given the reduced adsorptive capacity and restricted porosity of the sediments, the authors were able to conclude that the presence of biphytane, along with other molecular fossils, suggests the existence of archaea in the Late Archean sedimentary environments and in subsurface hydrothermal settings.