Adapter is a short nucleotide sequence with a known sequence, which is ligated to both ends of the target nucleic acid fragment. During sequencing, it hybridizes with the known sequence on the sequencing chips to combine the library to the chip, and then start sequencing. With the development of sequencing technology. The Y-type adapter of Illumina platform commonly used in sequencing contain P5/P7, Index, and Rd1/Rd2 SP sequences. The P5/P7 sequence was paired with the sequence on the sequencing chip, and the fragment to be tested was fixed on Flowcell to complete bridge amplification. Yeasen's team has developed various types of adapters suitable different platforms, you can contact us to know how to choose them.