A computer-implemented method for storing information into a polynucleotide is provided including using multiple types of nucleotide fragments, wherein each of the nucleotide fragments has an individually different sequence of bases, configuring multiple composite fragments, wherein each of the composite fragments has a set of the nucleotide fragments with different ratios of the nucleotide fragments, and encoding, via an encoder, the information into the composite fragments.

Techniques for achieving reductions in cost of encoding and decoding operations used in DNA data storage systems to facilitate reducing errors in those encoding and decoding operations while accounting for a code structure used during the encoding and decoding by constructing and using insertion-deletion-substitution (IDS) trellises for multiple traces are disclosed. A DNA sequencing channel is used to randomly sample and sequence DNA strands to generate noisy traces. Multiple trellises are independently constructed for each respective noisy trace. A forward-backward algorithm is run on each trellis to compute posterior marginal probabilities for vertices included in each trellises. An estimate of the data message sequence is then computed.

Data segments derived from stored oligonucleotides or oligos are decoded, each oligo comprising nucleotides representing information units distributed within segment addresses and payloads, the addresses enabling to order the payloads. The addresses are extracted and the payloads are ordered in function of those addresses. The segments are further clustered into segment clusters in function of edit distances between reference addresses and the extracted addresses, each of those clusters being associated with one of the reference addresses. Cluster payloads associated respectively with at least part of the clusters are determined, and those cluster payloads are ordered in function of the reference addresses of the clusters associated with the cluster payloads.