What Is the Singular Indexing Strategy?

When pooling unique libraries within a single lane, use an indexing strategy.

Singular Genomics provides high-quality, empirically tested unique dual-indexed barcodes. The Singular Genomics Unique Dual Index (UDI) design consists of 12 bp sequences. Efficient demultiplexing can be achieved by sequencing the first 8 bp of the index, although we recommend sequencing the full index length when possible.

If you want to use your own custom indices, make sure your index design avoids misassignment of reads and tolerates several types of errors, including those introduced during index synthesis. The index sequences must be as divergent as possible while having similar GC content and avoiding extended homopolymer stretches. An index should best be at least 3 changes (insertions, deletions, and/or substitutions) away from another index sequence. This minimizes the possibility for misassignment.

The following provides some additional considerations you should evaluate when designing your own indices:

• Index Length

• Error Detection

• Error Correction

• Single or Dual Indexing

• Unique or Combinatorial Indexing

• Unique Molecular Identifiers

See the Adapters and Indices for the G4 Sequencing Platform Reference Guide for more information on adapters and indices.

For more information, see the G4 Best Practices and Quality Control Guide, reach out to your Field Application Scientist, or contact Customer Care.

October 2023