Genomic DNA extraction of pure Thermococcales cultures

This protocol is adapted from a lab protocol made by Axel Thiel. The goal of this protocol was to simplify it to faster obtain genomic DNA from cell cultures. This protocol can be used for Thermococcales but could be used for other archaea. The protocol is adapted for small culture volume (1 mL to 20 mL) of cells in the stationary phase of growth; for example, 1mL of culture is enough to obtain genomic DNA for PCR whereas 20 mL is necessary to send sufficient genomic DNA for sequencing. Briefly, after centrifugation, the cellular pellet will be mixed with detergent (Sarkosyl 10% and SDS 10%) and proteinase K. After heating at 55°C, RNAse can be used if genomic DNA will be sequenced. Then a purification by phenol/chloroform/ isoamyl alcohol will be done. After centrifugation, genomic DNA will be washed by ethanol 70% and dry before being resuspended into water or TE buffer.