title: Amplicon liberates for the V3-V4 region of the 16S rDNA
design: Amplicon liberates were constructed for PE250 sequencing strategy through the upgraded Illumina sequencing platform (Novogene, Germany) using bacterial fused EUB8F and 1492R primers for the V3-V4 region of the 16S rDNA. PCR products will subsequently be purified using the QIAquick PCR purification kit. A second amplification will be performed to obtain amplicons of the V4 region using 515F and 806R primers, with an Illumina adapter and an 8-nucleotide barcode at the 5-end