Samples for major ion (Na+, K+, Ca2+, Mg2+, Cl–, SO4 2–, NO3 – and HCO3 −) analysis were collected in 500 mL polyethylene bottles.
Water samples for major ions analysis were initially filtrated through a 0.45 μm membrane filter and then collected in a pre-clean 15 ml plastic bottle, and stored at 4 °C until analysis.
In total, 24 rock samples for major element analyses, 9 rock samples for trace element analyses, and 46 rock samples for U-Pb zircon dating were collected from the four locations, the Seoseok-dae, Ipseok-dae, Gwangseok-dae, and Chotdae-bong colonnades (Tables 1 and 2 and Additional file 1: Table S1).
The analyses of the acidified samples for major (Na, K, Ca, Mg) and trace elements (Li, B, Fe, Cu, Zn, As, Rb, Sr, Mo, Cs, U, Ba) with ICP-MS at the Institute of Mineralogy and Geochemistry IMG at KIT showed a high reproducibility.
Samples for major ion concentrations were collected in plastic bottles.
Those authors concluded that RNAlater is an excellent storage agent for yeast cells and, most likely, for other cell types and tissues, to preserve the samples for major "omics" techniques and microscopic analyses (65).
Water sampling for major ion chemistry was performed at a proglacial hydrometric station and from subglacial outflows from May to September 2011.
For the second step, the pressed materials were inserted into a MagiXPro X – Ray Fluorescence Spectrometer for a period of 20 minutes / sample for major elements and 1.5 hours / sample for the minor elements.
Water samples collected for major ions and Sr-isotope analyses were stored in small polyethene bottles, while for isotope analysis of H and O, the samples were stored in glass bottles.
To prevent the formation of metal hydroxide complexes, samples for the major and trace elements were acidified with sub-boiled nitric acid (HNO3) to pH < 2 immediately after sampling.
Only samples for which Major et al. predicted full genotypes were considered, resulting in 12 HapMap WGS and 161 1000 Genomes Project datasets.
