This reference document provides the nucleotide sequences that comprise the Unique Dual Index (UDI) Primers of the Twist Universal Adapter System for use with Illumina sequencing technologies. The primers are configured in 96 well plates and are available in 16 or 96 sample formats. In the 96 sample format, 4 unique plates are available to allow for multiplexing 384 samples in a single sequencing run.Use the spreadsheet to copy the index sequences to create your own sample sheet for demultiplexing following sequencing. Or Edit and use the sample sheet template provided for Illumina sequencers and UDI plate(s) to demultiplex following sequencing.