Illumina adapter portfolio

The first step of sequencing is to construct a library from DNA or RNA. A library contains DNA inserts flanked on each side by an adapter, as shown in Fig. 1:

Figure 1: Schematic representation of a dual-indexed library fragment

Adapters contain:

• Sequences that allow the library to bind and generate clusters on the flow cell (p5 and p7 sequences)

• Sequencing primer binding sites to initiate sequencing (Rd1 SP and Rd2 SP)

• Index sequences (Index 1 and, where applicable, Index 2), which are sample identifiers that allow multiplexing/pooling of multiple samples in a single sequencing run or flow cell lane.

Illumina offers a wide range of adapter kits to allow flexibility and multiple indexing strategies. Illumina adapter kits differ from one another based on the number of samples they support, the length and sequences of the indexes, as well as the chemistry by which they attach to the insert fragment.

The tables below list the product specifications of the Illumina adapter kits:

• Plexity refers to the number of unique index sequences per kit

• Index Lengths refers to the number of cycles of sequencing required to read Index 1 and Index 2, respectively

  

1Formerly known as Nextera DNA Flex 2Formerly known as Nextera Flex for Enrichment 3Formerly known as IDT for Illumina Nextera DNA UD Indexes Set A-D 4This library prep kit is validated with v1 sets A & B, and v2 sets C & D only

Useful links

• Understanding unique dual indexes (UDI)

• Index Adapters Pooling Guide

• Illumina Adapter Sequences

For any feedback or questions regarding this article (Illumina Knowledge Article #3275), contact Illumina Technical Support [e-mail].