NEXTflex® Dual-Indexed DNA Barcodes NEXTFLEX® Unique Dual Index Barcodes

Illumina-compatible adapters for deep multiplexing of up to 192 samples

Catalog# Product Name Quantity US List Price
NEXTflex® Dual-Indexed DNA Barcodes (1 - 96) 768 rxns $7,133 Buy Now
NEXTflex® Dual-Indexed DNA Barcodes (97 – 192)
768 rxns $7,133 Buy Now


  • Enables deep multiplexing of Illumina DNA libraries for NGS applications
  • 8 nt index contained within adapter sequence
  • Increase your sequencing scale by pooling up to 192 samples on a single flow cell
  • The kits are supplied in a 96-well plate format
  • Compatible with Illumina next-generation sequencing platforms


Do you need a solution to mitigate index hopping and the spread of signal on patterned flow cells on Illumina® sequencers? If so, read about the new NEXTflex® Unique Dual Index Barcodes.

The NEXTflex® Dual-Indexed DNA Barcodes are two kits that each contain 96 combinatorial dual indexed barcoded adapters for Illumina® library prep which enable deep multiplexing of NGS sequencing samples compatible with high-throughput automation.

They significantly increase scale, while reducing costs by allowing the user to pool up to 192 samples in a single flow cell.


Libraries made using the NEXTflex Dual-Indexed DNA Barcodes can be combined with single index libraries using a dual index sequencing read primer.

The NEXTflex Dual-Indexed DNA Barcodes can be used with single, paired-end and multiplex reads, and are compatible with the NEXTflex™ Rapid DNA-Seq Kit, the NEXTflex™ Methyl DNA-Seq Kit, the NEXTflex Cell Free DNA-Seq Kit and other genomic DNA library prep kits.

For larger volume requirements, customized and bulk packaging is available. Please contact for further information.

Kit Specs

The NEXTflex Dual-Indexed DNA Barcodes contain 8 reactions each of 96 unique Illumina-compatible adapters, enabling the user to multiplex up to 192 samples. This kit is shipped on dry ice.

NEXTflex™ Dual-Indexed DNA Barcodes


Dual-Indexed Single Read and Paired End Sequencing

Kit Contents

NEXTflex™ Dual-Indexed Adapter (25 µM)
NEXTflex™ Primer Mix (12.5 µM)

Sequences of NEXTflex Dual-Indexed DNA Barcode Indexes - Excel / PDF

Instructions for installing NEXTflex Barcode Indices in Illumina Experiment Manager


What Sequencing Primers Do I Use for Dual-Indexed Libraries?

Libraries made with the NEXTflex™ Dual-Indexed DNA Barcodes differ from libraries made with the NEXTflex DNA Barcodes in that they have two index sequences, as opposed to a single barcode index. Depending on the sequencing platform and flowcell being used, dual-indexed libraries may require the use of special sequencing primers in place of the primers found in the TruSeq Cluster Kit.

Sequencing of dual-indexed libraries on the MiSeq does not require the use of the TruSeq Dual Index Sequencing Primer Box in addition to the MiSeq Reagent Kit.

Sequencing dual-indexed libraries on the HiSeq or GAIIx, however, may require the use of the TruSeq Dual Index Sequencing Box. The TruSeq Dual Index Sequencing Box, SR (Illumina cat. # FC-121-1003) is required when sequencing dual-indexed libraries on a single-read flow cell. In this case, the Index 2 (i5) Sequencing Primer Mix, HP9, must be loaded in position 16 on the flowcell. If sequencing dual-indexed libraries on a paired-end flow cell for HiSeq or GAIIx, the TruSeq Dual Index Sequencing Box is not required, as the Index 2 primer is grafted on the flow cell.

In summary, sequencing dual-indexed libraries requires additional primers only if sequencing on a single-read flow cell on the HiSeq or GAIIx. Sequencing on a paired-end flow cell on the HiSeq or GAIIx or on the MiSeq does not require additional primers to be purchased in addition to the typical sequencing primer kit for each sequencer.

Flowchart describing Illumina sequencing with NEXTflex Dual-Indexed DNA Parcodes