VAHTS Universal Adapter Ligation Module for Illumina V2 (VAHTS) was the igation module for oriented optimization of libraries for Illumina high-throughput sequencing platform. Using this kit, the dT protruding connector sequence can be efficiently ligated to the end of a repair product containing a phosphate group at the 5 'end and a dA protruding 3' end. Compared with the conventional method, VAHTS Universal Adapter Ligation Module for Illumina V2 was used to obtain the single-tube reaction. The segmented DNA can be ligated directly after treatment with VAHTS Universal End preparation Module for Illumina V2 (N203-01/02) without additional product purification steps. Therefore, the requirement of initial DNA template is significantly reduced, and the experimental time is shortened. All reagents provided in the kit have undergone strict quality control and functional verification, which ensures the stability and repeatability of library preparation to a large extent.