title: blank sample for 16S rRNA sequence from snowpack
design: Blank sample (MilliQ water) for environmental DNA was extracted from filters using the PowerWater DNA Isolation Kit (MoBio, Carlsbad, CA, US) according to the manufacturer's instructions. The 16S rRNA fragment was amplified using bacterial primers 341F and 805R spanning the V3V4 hypervariable regions. Sequencing was performed on the MiSeq platform (Illumina, San Diego, USA) using paired-end reads (2 x 300 bp) by the Macrogen company (Macrogen Europe, Amsterdam, The Netherlands).