Uploaded August 2026 | Updated September 2026, 2 weeks ago
The main obstacle to reducing the cost of DNA-based data storage is the synthesis process. Composite DNA symbols leverage the inherent redundancy in synthesis by representing positions as mixtures of nucleotides, effectively increasing storage density. In this work, we further develop the theory of rank-modulated composite symbols, where information is determined by the relative ordering of motifs rather than exact frequency values. Unlike previous models that used fixed-length permutations and Kendall’s tau distances, we introduce a more faithful physical model considering insertion and deletion errors occurring at the “tail” of the ranking, the lower-frequency motifs. We establish a theoretical equivalence between tail deletion, insertion, and indel codes and present optimal code constructions for variable-length permutations. Furthermore, we extend these results to sequences of symbols using a Tail Tensor Permutation Code (TTPC) construction. Our findings provide both theoretical bounds and efficient practical tools for high-density, error-resilient DNA data storage systems. Furthermore, our results demonstrate that allowing variable permutation resolutions significantly enhances the flexibility and error-resilience of high-density DNA storage systems, offering a practical path toward reducing synthesis cycles without sacrificing reliability.
Presented by
Tomer Cohen, Technion
This is a presentation from the 2026 Storage and Computing with DNA Conference.
· Learn More about the SNIA DNA Data Storage Alliance: snia.org/groups/snia-dna-technology-affiliate
· SNIA Educational Library: snia.org/library
· X: twitter.com/SNIA
· LinkedIn: linkedin.com/company/snia
The main obstacle to reducing the cost of DNA-based data storage is the synthesis process. Composite DNA symbols leverage the inherent redundancy in synthesis by representing positions as mixtures of nucleotides, effectively increasing storage density. In this work, we further develop the theory of rank-modulated composite symbols, where information is determined by the relative ordering of motifs rather than exact frequency values. Unlike previous models that used fixed-length permutations and Kendall’s tau distances, we introduce a more faithful physical model considering insertion and deletion errors occurring at the “tail” of the ranking, the lower-frequency motifs. We establish a theoretical equivalence between tail deletion, insertion, and indel codes and present optimal code constructions for variable-length permutations. Furthermore, we extend these results to sequences of symbols using a Tail Tensor Permutation Code (TTPC) construction. Our findings provide both theoretical bounds and efficient practical tools for high-density, error-resilient DNA data storage systems. Furthermore, our results demonstrate that allowing variable permutation resolutions significantly enhances the flexibility and error-resilience of high-density DNA storage systems, offering a practical path toward reducing synthesis cycles without sacrificing reliability.
Presented by
Tomer Cohen, Technion
This is a presentation from the 2026 Storage and Computing with DNA Conference.
· Learn More about the SNIA DNA Data Storage Alliance: snia.org/groups/snia-dna-technology-affiliate
· SNIA Educational Library: snia.org/library
· X: twitter.com/SNIA
· LinkedIn: linkedin.com/company/snia





![Nanopore sequencing of synthetic libraries of RNA oligonucleotides
Photolithography is one of the very approaches that allow for the synthesis of nucleic acid microarrays in situ, and characteristic aspects of in situ microarray synthesis are high-throughput and high-density, delivering several hundreds of thousands of unique sequences in a single run and on a single, small surface (Figure 1). Microarray synthesis has traditionally focused on the preparation of DNA microarrays to obtain complex DNA libraries. These have been used in the context of DNA data storage, gene synthesis and other nanotechnology applications [1]. Recently, our group has shown that photolithography is amenable to prepare RNA microarrays as well, at identical throughput and density [2]. It remains the only available chemical approach that can deliver complex synthetic RNA libraries with total control on the sequence. RNA microarrays can be used to interrogate the sequence preference of enzymes and RNA-binding proteins, but they are also ideally poised to generate RNA libraries for off-array applications. We can produce pools of RNA sequences between 75 and 100-nt in length which can be sequenced directly by Nanopore sequencing without any intermediate purification step [3]. Our photolithography platform also allows for the introduction of biologically relevant base modifications, of which m6A, 5mC and inosine are already available and preliminary data shows that m6A can be accurately basecalled. Simultaneously, nanopore sequencing data returns crucial information on the synthetic error-rate of RNA photolithography. This talk will focus on presenting the technology of RNA photolithography and on describing how RNA libraries can be prepared and sequenced.
Presented by
Jory Lietard, University of Vienna
This is a presentation from the 2026 Storage and Computing with DNA Conference.
· Learn More about the SNIA DNA Data Storage Alliance: https://www.snia.org/groups/snia-dna-technology-affiliate
· SNIA Educational Library: https://snia.org/library
· X: https://twitter.com/SNIA
· LinkedIn: https://linkedin.com/company/snia/ Nanopore sequencing of synthetic libraries of RNA oligonucleotides](https://i.ytimg.com/vi/VNJYQbz7MTY/mqdefault.jpg)




