DNA-seq (DNA sequencing) is the process of determining the nucleic acid sequence – the order of nucleotides in DNA using the high-throughput sequencing method. Library preparation is a necessary step to transform DNA into a library which suitable for high-throughput sequencing. Yeasen provides the complete solution for DNA library preparation, including all the enzymes used in the processes of DNA library preparation, and kits. The DNA library preparation kits provided by Yeasen can be divided into two groups based on different principles, including mechanical fragmentation library preparation and enzymatic fragmentation library preparation.