An Encoding Table Corresponding to ASCII Codes for DNA Data Storage and a New Error Correction Method HMSA

Abstract

DNA storage stands out from other storage media due to its high capacity, eco-friendliness, long lifespan, high stability, low energy consumption, and low data maintenance costs. To standardize the DNA encoding system, maintain consistency in character representation and transmission, and link binary, base, and character together, this paper combines the encoding method with ASCII code to construct an ASCII-DNA encoding table. The encoding method can encode not only pure text information but also audio and video information and satisfies the GC content constraint and the homopolymer constraint, with the encoding density reaching 1.4 bits/nt. In particular, when encoding textual information, it directly skips the binary conversion process, which reduces the complexity of encoding, and increasing the encoding density to 1.6 bits/nt. In order to solve the problem of errors in sequences, under the influence of heuristic algorithms, this paper proposes a new error correction method (HMSA) by combining minimum Hamming distance, multiple sequence alignment, and encoding scheme. It can correct not only substitution, insertion, and deletion errors in Reads but also consecutive errors in Reads. It greatly improves the utilization of the Reads and avoids the waste of resources. Simulation results show that the recovery rate of Reads increases with the increasing number of sequencing times. When the number of erroneous bases in a 150nt sequence reaches 5nt, the error correction rate can exceed 96% by sequencing the base sequence only 10 times regardless of whether the errors are consecutive or not. Additionally, the HMSA error correction method is applicable to all coding schemes for lookup code table types.