Singular Genomics uses stem loop-shaped adapters as part of the library preparation process. After end-repair and A-tailing, stem loop adapters are ligated to the DNA ends. These adapters contain a cleavable site which, when cleaved, generates the substrate for PCR amplification. During PCR amplification, the primers add the S1/S2 sequences required for cluster generation on the Singular Genomics flow cell as well as 12 base pair unique dual indices, if indices are used. For more information regarding our adapter design, please refer to the Adapters and Indices for the G4 Sequencing Platform reference guide.