16S rDNA from size fractionated lake water (NC fraction from filtrate through GFC filtration)
Water samples were filtered (1.5  2 L) through previously autoclaved glass fiber filters (GF/C) using low vacuum filtration followed by filtration of the filtrate onto autoclaved nitrocellulose (NC) filters. DNA was extracted using the the DNeasy Power Water Kit from NC filters. Amplification of  16S rDNA V3-V4 region was done using, the two standard primers 341F-mod ILL (CCTAYGGGRBGCASCAG)  806R-ILL (GGACTACNNGGGTATCTAAT), (28 cycles).