This kit is a second-generation sequencing library preparation kit specifically designed for the V3-V4 region of bacterial 16S rDNA for use on the illumina platform. This reagent can achieve specific amplification of the V3-V4 region of 16S rDNA by one-step PCR and attach the splice containing index to construct a complete illumina library. This step is simpler and faster, and is more suitable for automatic library construction. The target area of this kit is approximately 450bp, and sequencing using the illumina Miseq platform PE300 or Novaseq PE250 strategy is recommended.