title: 16SrRNA metagenome of low light coral
design: For DNA extraction each fragment was crushed to powder on liquid N2 with a mortar and pestle. About 500 mg of powder was used to extract DNA following the Qiagen DNeasy Plant Mini Kit (Hilden, Germany) manual with an additional 1 min centrifugation step (17,000 g) after the final washing. Extracted DNA was quantified on a Multiscan GO (Thermo Scientific) photometer. Extracted DNA and a negative control sample (extraction buffers without DNA) were sent for amplification and sequencing on the Illumina MiSeq platform at GENEWIZ (Suzhou, China) where 1st stage PCRs were performed in triplicate using 784F and 1061R primers (including underlined Illumina adaptor overhangs; Illumina San Diego, CA, USA) that target the V5-V6 regions of the 16S rRNA gene [34]: forward primer 5-TCGTCGGCAGCGTCAGATGTGTATAAGAGACAGAGGATTAGATACCCTGGTA-3, reverse primer 5-GTCTCGTGGGCTCGGAGATGTGTATAAGAGACAGCRRCACGAGCTGACGAC-3. 1st stage PCRs were run for 25 cycles and conditions for 1st stage PCRs and library preparations followed GENEWIZ in-house procedures.