16S rRNA gene sequencing of OSCC  sample1
The  amplification of a V1-V2 hypervariable region of the 16S rRNA gene was  performed with universal primers 27F: 5-AGAGTTTGATCMTGGCTCAG-3 and 338R:  5-GCTGCCTCCCGTAGGAGT-3 which also contained illumine adapter sequences.  Barcodes were attached to the 5 terminus of the forward primers to multiplex  the samples during sequencing. The PCR libraries were barcoded using the  Illumina dual-index system (Nextera XT v2 Index Kit Set A).