title: Exp1_SW_doc_D14_2
design: PCRs were run in triplicate at a total volume of 20  l using the Qiagen multiplex PCR Master Mix with ~10-50 ng DNA for the coral and ~1-10 ng DNA for seawater samples, respectively.  The final primer concentration was adjusted to 0.25  M. The PCR conditions were set as follows: 95 C for 15 minutes, followed by 25 cycles of 95 C for 30 seconds, 55 C for 30 seconds and 72 C for 30 seconds, with a final extension time of 10 minutes at 72 C. Triplicate PCRs for each sample were pooled and amplification was visualized on the Bioanalyzer (Agilent Technologies, Santa Clara, USA). Samples underwent an index PCR amplification following the Illumina 16S metagenomic sequencing library preparation protocol, combined and run on a 2% ultra-pure agarose gel (Ultrapure Agarose, Life Technologies), and cut out on a non-UV transilluminator (Dark Reader, Clare Chemical Research, Dolores, USA) to remove excess primer. The DNA in the gel was purified following the Zymoclean DNA large fragment recovery kit (Zymo Research, Irvine, USA) with two elutions at 10  l. The metagenome libraries were sequenced on one lane on the Illumina MiSeq platform with 25% phiX control at the KAUST sequencing facility. The libraries were sequenced using 2x300 bp overlapping paired-end reads.