Which sequences do I need to enter into my sample sheet for demultiplexing with Illumina software tools?

The i7 and i5 sequences for all Lexogen UDI 12 nt Unique Dual Indexing Sets (A1 - A4 and B1) are available for download at on our Document Webpage.

For each set, i5 sequences are indicated in forward and reverse (i5rc) orientation. Depending on the set chosen and the instrument used for the sequencing, either the i5 forward or i5 reverse sequence must be entered in the sample sheet for successful demultiplexing.

How to choose the correct i5 sequence orientation?

UDI Sets A and B can be sequenced on any Illumina instrument, regardless of the workflow utilized.

• If you are using UDI Sets A on a sequencing instrument using the forward workflow or the UDI Set B on a sequencer using the reverse complement workflow, the i5 forward sequence must be entered in the sample sheet.

Example: i512A_0002 forward sequence CCCAGTTACTAA

• If you are using UDI Sets A on a sequencing instrument using the reverse workflow or vice-versa (UDI Set B on a sequencer using the forward workflow), the reverse complement i5 sequences must be entered in the sample sheet.

Example: i512A_0002 forward sequence TTAGTAACTGGG

NOTE: Please see this FAQ to check the Illumina sequencers´ workflow and which UDI set to choose for your experiment.