Table 1.

Sediment coring sites, core depths sampled, and associated molecular analyses conducted.

Date sampled	Site	Estimated depth sub-sampled (cm)a	Sample ID	DNA	RNA	aRNA	iTag SSU rRNA V4 region (505F-806R)	Clone libraries Archaea SSU rRNA gene (109F-915R)b	Clone libraries Archaea SSU rRNA gene (20F-958R)b	DGGE Archaea SSU rRNA V3 region (GC347F-UNIV519R)c
Apr-2010	Ikroavik	1–17	Ikr10-A	+	–	–	–	+ii	–	+
Apr-2010	Qalluuraq	1–58	Qal10	+	–	–	–	–	–	+
Apr-2010	Sukok C	1–31	SukC10	+	–	–	–	–	–	+
Oct-2010	Ikroavik	2–28	Ikr10-O	+	–	–	–	+ii	–	+
Oct-2010	Siqlukaq	10–50	Siq10	+	–	–	–	+ii	–	+
Oct-2010	Sukok Seep	2–106	SukS10	+	–	–	–	+ii	–	+
22-Oct-2011	Siqlukaq	6–7	Siq-U	+	+	+	+i	–	+i	–
	Siqlukaq	13–14	Siq-M	+	+	+	+i	–	+i	–
	Siqlukaq	23–24	Siq-L	+	+	+	+i	–	+i	–
24-Oct-2011	Sukok B	6–8	SukB-U	+	+	+	+i	–	+i	–
	Sukok B	11–14	SukB-M	+	+	+	+i	–	+i	–
	Sukok B	21–24	SukB-L	+	+	+	+i	–	+i	–
20-Oct-2011	Sukok Seep	7–9	SukS-U	+	–	+	+i	–	+i	–
	Sukok Seep	16–19	SukS-M	+	–	+	+i	–	+i	–
	Sukok Seep	22–24	SukS-L	+	–	+	+i	–	+i	–

The geographic positions of the 2011 coring sites were reported in (Matheus Carnevali et al., 2015). 2010 coring sites were: Ikr10: 71° 14.036′N, 156° 38.349′W, Siq10: 71° 10.486′N, 156° 53.891′W, SukS10: 71° 04.455′N, 156° 49.250′W, and Qal10: 70° 22.672′N, 157° 20.927′W (60 miles to the south). The shaded area highlights samples used for iTag surveys.

^aTwo to 10 subsamples were collected per core. See Materials and Methods section for details about the number of samples per depth interval.

^bSamples from discrete depth intervals were pooled for clone libraries construction to study Archaea phylogeny in arctic thermokarst lakes. Latitude and longitude of the coring sites were reported in Matheus Carnevali et al. (2015).

^cDiscrete depth intervals were loaded onto the gel to survey archaeal diversity (see Figure S2 for details).

ⁱDNA Extraction method i.

ⁱⁱDNA Extraction method ii.