Full-length adapters are compatible with ligation-based library construction workflows for direct and targeted multiplexed DNA and RNA (cDNA) sequencing applications on the Illumina® platform. Since sequencing barcodes are added during an adapter ligation step, full-length adapters are particularly well suited for PCR-free workflows.

KAPA Unique Dual-Indexed (UDI) and KAPA Dual-Indexed (DI) Adapters all have a standard Illumina adapter backbone. They are therefore easily incorporated in new and existing Illumina sequencing workflows, and do not require customized sequencing or indexing primers. A combination of 8-nt sequencing barcodes on each of the i5 and i7 adapter oligos supports paired-end sequencing on 2- and 4-channel Illumina instruments. KAPA UDI Adapters and KAPA DI Adapters both support a broad range of sample pooling (2- plex up to 96-plex, as appropriate for your workflow), for target enrichment and/or sequencing.

Your choice of unique vs. combinatorial dual-indexed adapters should be determined by your sequencing instrument and the sensitivity of your application to index misassignment. KAPA UDI Adapters employ 192 non-redundant barcodes for the 96 unique dual-index combinations, whereas KAPA DI Adapters offer a combinatorial approach (twelve i7 x eight i5 barcodes = 96 dual index combinations). Unique dual-indexing is recommended for all applications and Illumina sequencers, whereas combinatorial dual-indexing may suffice for older generation instruments with non-patterned flow cells.1,2

Refer to this table to determine whether KAPA UDI Adapters or KAPA DI Adapters are best for your application.

Product highlights


Fewer misassigned reads improve confidence in results

  • Index misassignment during multiplexed sequencing may be the result of index hopping, barcode or sample cross-contamination, template switching during PCR amplification of pooled samples, and/or sequencing/analysis errors; some of which may be mitigated by adapter design and quality
  • Unique dual-index combinations in KAPA UDI Adapters allow reads with unexpected barcode combinations to be filtered out prior to data analysis
  • KAPA Adapters are manufactured using stringent procedures and undergo sequencing-based QC testing to reduce the potential for index misassignment resulting from barcode cross-contamination


High-performance, complete workflows for a wide range of applications

  • High-performance library construction workflows require appropriate, high-quality accessories such as adapters and beads to achieve optimal library yields and quality
  • KAPA Adapters undergo functional testing in an NGS library construction workflow to confirm high levels of library construction efficiency, minimal levels of adapter-dimer formation and consistent performance across all 96 index combinations
  • KAPA UDI and DI Adapters have been validated for use with KAPA HyperPrep, KAPA HyperPlus and all KAPA RNA HyperPrep library preparation kits


Flexible and efficient PCR-free human whole-genome sequencing

  • Even a small amount of library amplification may introduce bias which results in uneven coverage and the requirement for more sequencing; particularly when sequencing human and other complex genomes, or microbial genomes with extreme GC-content
  • PCR-free workflows have become the gold standard for human whole-genome sequencing (WGS)
  • High-quality, full-length KAPA Adapters used in combination with KAPA HyperPrep Kits support the flexible and highly efficient library construction protocols needed for high-throughput, PCR-free human WGS
  1. https://www.illumina.com/science/education/minimizing-index-hopping.html. Accessed February 2019.
  2. Costello M, et al. BMC Genomics. 2018;19:332