Method and system for dna storage based on multi-molecular channels

Abstract

The application provides a DNA storage method and system based on a multi-molecule channel, comprising: determining a modification proportion of a preset modification site on a DNA chain, the modification proportion being a ratio of modified DNA molecules on the preset modification site to all DNA molecules; dividing a range of the ratio into multiple concentration categories according to a preset gradient, each concentration category corresponding to a code symbol, and forming a multi-ary code system; classifying the modification proportion into a corresponding concentration category, and reading out the code symbol corresponding to the concentration category as information stored by the preset modification site. The single modification site can represent a number of information states that is more than that of a traditional sequence coding mode according to the concentration category into which the modification proportion falls, thereby improving the information storage density of the DNA molecules.

Description

Technical Field

[0001] This invention relates to the field of information storage technology, and in particular to a DNA storage method and system based on multi-molecular channels. Background Technology

[0002] Existing DNA data storage methods primarily encode information by designing the base sequence of DNA molecules, using the types or order of bases as information carriers. In this approach, a single physical site on the DNA strand can only represent a limited number of states, restricting the amount of information stored per unit site and making it difficult to further increase storage density. Summary of the Invention

[0003] This invention provides a DNA storage method and system based on multi-molecular channels to solve the problem that in the prior art, a single physical site on the DNA strand can only represent a limited number of states, which limits the amount of information stored per unit site and makes it difficult to further improve the storage density.

[0004] This invention provides a DNA storage method, comprising: The modification ratio of preset modification sites on the DNA strand is determined, wherein the modification ratio is the ratio of DNA molecules modified at the preset modification sites to all DNA molecules. The range of the ratio is divided into multiple concentration categories according to a preset gradient, and each concentration category corresponds to a coding symbol, forming a multi-base coding system; The modification ratio is assigned to the corresponding concentration category, and the encoded symbol corresponding to the concentration category is read out as the information stored at the preset modification site.

[0005] According to a DNA storage method provided by the present invention, the step of dividing the range of the ratio into multiple concentration categories according to a preset gradient includes: The range of the ratio is divided into N concentration categories, where N is an integer greater than or equal to 2. Each concentration category corresponds to a different coding symbol, forming an N-ary coding system. When N=2, the modification ratio of 0% is classified as the first concentration category, corresponding to the code symbol 0; the modification ratio of 100% is classified as the second concentration category, corresponding to the code symbol 1. Alternatively, when N=4, the modification ratios of 0%, 33.3%, 66.6%, and 100% are divided into four concentration categories, corresponding to the coding symbols 0, 1, 2, and 3 respectively; Alternatively, when N=8, the modification ratios of 0%, 14.3%, 28.6%, 42.9%, 57.1%, 71.4%, 85.7%, and 100% are divided into eight concentration categories, corresponding to the coding symbols 0 to 7 respectively.

[0006] According to a DNA storage method provided by the present invention, the modification at the preset modification site is performed by at least one of methylation, phosphorylation, carboxylation or thiolation.

[0007] According to a DNA storage method provided by the present invention, the methylation modification is performed using 5-methylcytosine modification, and the preset modification site is selected from the CpG dinucleotide site.

[0008] According to a DNA storage method provided by the present invention, the DNA strand is composed of multiple sub-sequences of predetermined length, and a predetermined number of predetermined modification sites are distributed on each sub-sequence.

[0009] According to a DNA storage method provided by the present invention, the determination of the modification ratio of preset modification sites on the DNA strand includes: Nanopore sequencing was performed on the DNA strand to obtain the electrical signal of the DNA strand; The electrical signal is subjected to base identification to obtain the modification ratio of the preset modification sites.

[0010] According to a DNA storage method provided by the present invention, after classifying the modification ratio into the corresponding concentration category, the method further includes: Analyze the error distribution characteristics of the modified ratios and screen out error-prone sites; RS error correction is performed on the acquired data. If RS error correction fails, soft decoding error correction is performed on the error-prone points, and RS error correction is iterated to restore the stored information.

[0011] According to a DNA storage method provided by the present invention, the step of performing soft decoding error correction on the error-prone sites includes: The error-prone points are corrected using a software decoding error correction method, and RS error correction is performed iteratively. The error distribution feature is that the errors in the modification ratio are concentrated in the adjacent concentration categories of the correct concentration category.

[0012] According to a DNA storage method provided by the present invention, the step of reading out the information stored as the preset modification site using the coding symbol corresponding to the concentration category includes: The encoded symbols are converted into at least one information type, either image data or text data, and output.

[0013] This invention provides a DNA storage system, comprising: The measurement module is used to measure the modification ratio of preset modification sites on the DNA strand, wherein the modification ratio is the ratio of DNA molecules modified at the preset modification sites to all DNA molecules. The division module is used to divide the range of the ratio into multiple concentration categories according to a preset gradient. Each concentration category corresponds to a coding symbol, forming a multi-base coding system. The modification ratio is assigned to the corresponding concentration category, and the encoded symbol corresponding to the concentration category is read out as the information stored at the preset modification site.

[0014] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the DNA storage method described above.

[0015] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the DNA storage method as described above.

[0016] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the DNA storage method as described above.

[0017] The DNA storage method and system based on multi-molecule channels provided by this invention determines the modification ratio of a preset modification site, divides the range of ratios into multiple concentration categories according to a preset gradient, and each concentration category corresponds to a coding symbol, forming a multi-level coding system. The measured modification ratio is assigned to the corresponding concentration category, and the corresponding coding symbol is used to read out the information stored at that modification site. This allows a single modification site to represent more information states than traditional sequence coding methods, depending on the concentration category to which its modification ratio falls, thereby increasing the information storage density of the DNA molecule. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a flowchart illustrating the DNA storage method provided by the present invention.

[0020] Figure 2 This is a schematic diagram of the multi-level encoding of DNA modification concentration provided by the present invention.

[0021] Figure 3 This is a PAGE result image of the DNA template carrying information provided by the present invention.

[0022] Figure 4 This is a schematic diagram showing the methylation probability at different DNA template positions when storing "Encrypt" according to the present invention.

[0023] Figure 5 This is a schematic diagram of the quaternary experimental results and accuracy provided by the present invention.

[0024] Figure 6 This is a schematic diagram of the DNA storage system provided by the present invention. Figure 7 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0026] Figure 1 This is a flowchart illustrating the DNA storage method provided by the present invention.

[0027] like Figure 1 As shown, this embodiment provides a DNA storage method, including: 101. Determine the modification ratio of the preset modification sites on the DNA strand. The modification ratio is the ratio of DNA molecules modified at the preset modification sites to all DNA molecules.

[0028] Specifically, the modification ratio is the ratio of modified DNA molecules at a predetermined modification site to all DNA molecules at that site. This includes concentration ratios, quantity ratios, or fluorescence and density ratios caused by related factors. The ratio can originate from the composition, structure, modification, spatial arrangement, reaction process, detection signal, sequencing results, amplification results, statistical characteristics, or combinations thereof of DNA molecules, and it serves as the core basis for information encoding. First, drawing on the natural concentration-dependent regulatory mechanisms in biological systems, a dedicated information storage DNA chain is designed and prepared. Precise modification sites for carrying information are precisely set on this DNA chain. Then, nanopore sequencing technology is used to read the concentration data of modification sites on all template strands, obtaining the modification ratio value for each site. This value ranges from 0% to 100% of the modification concentration. Providing accurate and stable basic data for subsequent multi-level encoding ensures the accuracy of information storage and retrieval from the source, which is a prerequisite for achieving concentration-bit encoding.

[0029] 102. Divide the range of ratios into multiple concentration categories according to a preset gradient. Each concentration category corresponds to a coding symbol, forming a multi-base coding system.

[0030] Specifically, the ratio ranges from 0% to 100%. This continuous range is divided into multiple distinct and non-overlapping concentration categories according to a preset gradient. Each concentration category corresponds to a unique coding symbol, thus constructing a multi-level coding system and forming a coding core based on multiple molecular channels. This breaks the limitation of traditional DNA storage relying solely on base type / sequence encoding, no longer depending solely on the sequence itself to carry information. It allows a single physical modification site to represent multiple information states, realizing one modification concentration corresponding to multiple binary bits, fundamentally improving the information storage density and coding flexibility of DNA molecules, combined with... Figure 2 The diagram showing the multi-level coding of DNA modification concentrations provides a clear view of the one-to-one correspondence between concentration categories and coding symbols, demonstrating the construction logic of the multi-level coding.

[0031] Figure 2 In this diagram, "Epigenetic pattern" refers to an information coding pattern constructed using epigenetic modifications such as DNA methylation, and is the core foundation of multi-molecular channel coding. "M" represents methylation, specifically 5-methylcytosine (5mC) modification, and is the identifier for the modification state in the diagram. "One site" indicates that the coding uses a single pre-defined modification site on the DNA strand as the basic coding unit; a single site can achieve multi-level coding through modification concentration. "The proportion of bricks" represents the brick ratio, controlling the mixing ratio of modified and unmodified bricks to achieve a modification concentration gradient. "DNA template" refers to the specially designed long DNA chain carrier used to carry information. "C" represents the cytosine base in the DNA strand, the core base of the CpG dinucleotide site, and the target site for methylation modification. "CAT" represents the base sequence fragment on the DNA template, used to indicate the DNA sequence environment where the modification site is located. The three-bit binary codes (000, 001, 010, 011, 100, 101, 110, 111) correspond to the binary equivalents of octal codes 0-7, embodying the core innovation of one modification concentration corresponding to multiple binary codes, meaning a single modification site can carry 3 bits of binary information. The percentage values ​​(14.3%, 28.6%, 42.9%, 57.1%, 71.4%, 85.7%, 100%) represent the octal code concentration gradient, corresponding to the modification ratio division of octal codes 0-7, and are the core numerical basis for mapping concentration categories to coding symbols.

[0032] 103. Assign the modification ratio to the corresponding concentration category, and read out the information stored as the preset modification site using the corresponding coding symbol of the concentration category.

[0033] Specifically, the modification ratio of each preset modification site obtained from sequencing is precisely matched to a pre-defined concentration category. The coding symbol bound to that category is then directly read out as the information stored at that preset modification site, completing the conversion from biomolecular concentration signal to digital coding signal. This achieves precise mapping and restoration of DNA modification concentration to digital code, providing core support for subsequent information output and error correction verification, and ensuring that the stored information can be stably and completely read.

[0034] Furthermore, based on the above embodiments, this embodiment divides the concentration into multiple categories according to a preset gradient, including: dividing the range of ratios into N concentration categories, where N is an integer greater than or equal to 2, and each concentration category corresponds to a different coding symbol, forming an N-ary coding system; when N=2, the modification ratio of 0% is classified as the first concentration category, corresponding to the coding symbol 0; the modification ratio of 100% is classified as the second concentration category, corresponding to the coding symbol 1; or, when N=4, the modification ratios of 0%, 33.3%, 66.6%, and 100% are respectively divided into four concentration categories, corresponding to the coding symbols 0, 1, 2, and 3 respectively; or, when N=8, the modification ratios of 0%, 14.3%, 28.6%, 42.9%, 57.1%, 71.4%, 85.7%, and 100% are respectively divided into eight concentration categories, corresponding to the coding symbols 0 to 7 respectively.

[0035] Specifically, the ratio range of 0%-100% is divided into N concentration categories (N is an integer greater than or equal to 2), with each category corresponding to a different independent coding symbol, forming an N-ary coding system. In this embodiment, the storage density increases synchronously with the number of distinguishable concentration categories. If there are N distinguishable concentration categories, the storage density increase factor is log2N. The specific division method and its effects are as follows: Binary encoding (N=2): A 0% modification ratio is classified as the first concentration category, corresponding to the encoding symbol 0; a 100% modification ratio is classified as the second concentration category, corresponding to the encoding symbol 1. This is the basic stable encoding scheme. The encoding logic is simple, detection is easy, and it is suitable for scenarios with high stability requirements and moderate storage density requirements. It is the basic form of multi-level encoding.

[0036] Quaternary encoding (N=4): The modification percentages of 0%, 33.3%, 66.6%, and 100% are divided into four concentration categories, corresponding to the encoding symbols 0, 1, 2, and 3 respectively. This directly increases storage density by twice that of binary encoding, significantly improving the information capacity per unit site while maintaining detection accuracy.

[0037] Octal encoding (N=8): The modification percentages of 0%, 14.3%, 28.6%, 42.9%, 57.1%, 71.4%, 85.7%, and 100% are divided into eight concentration categories, corresponding to the encoding symbols 0 to 7 respectively. This method offers three times the storage density of binary encoding, making it a preferred solution for high-density storage and maximizing the information-carrying potential of DNA molecules.

[0038] All of the above classification rules are in the appendix. Figure 2 The system is clearly labeled, allowing for flexible selection of single-base or mixed-base encoding based on actual storage needs. Through gradient partitioning, it achieves composite encoding characteristics and dynamic adjustment capabilities, effectively improving storage density.

[0039] Furthermore, based on the above embodiments, the modification at the preset modification site in this embodiment adopts at least one of methylation modification, phosphorylation modification, carboxylation modification or thiolation modification.

[0040] Specifically, the modification at the preset modification site can employ any one or more combinations of methylation, phosphorylation, carboxylation, and thiolation. Methylation uses 5-methylcytosine (5mC) as the core epigenetic modification. The preset modification site is the CpG dinucleotide site, a naturally occurring and highly efficient site for DNA methylation, exhibiting high modification efficiency and stable modification state. Nanopore sequencing can stably identify and quantify the modification ratio at this site. This embodiment precisely controls the modification concentration gradient by adjusting the mixing ratio of modified and unmodified type blocks, allowing for the preparation of different concentration ratios without altering the DNA base sequence. The effects and suitable scenarios for each modification method are as follows: Methylation modification: extremely stable and not easily degraded, and can be accurately identified by nanopore sequencing, making it the first choice for long-term storage; Phosphorylation modification: The modification reaction is highly efficient and easy to operate, making it suitable for rapid coding and writing scenarios; Carboxylation modification: improves the water solubility of DNA molecules, facilitates sequencing and subsequent data processing, and is suitable for aqueous storage systems; Thiolization modification: enhances the DNA molecule's resistance to degradation, extends its storage life, and is suitable for scenarios requiring high stability.

[0041] By enriching the selection dimensions of modifications, the scenario adaptability and flexibility of the solution are improved. The concentration can be precisely controlled by the mixing ratio of movable type blocks, providing a reliable molecular basis for multi-base encoding.

[0042] Furthermore, based on the above embodiments, in this embodiment the DNA chain consists of multiple sub-sequences of predetermined length, with a predetermined number of predetermined modification sites distributed on each sub-sequence.

[0043] Specifically, the DNA strand used for storing information consists of at least one subsequence of a predetermined length, with a predetermined number of independent, pre-defined modification sites evenly distributed on each subsequence, preferably CpG dinucleotide sites. The entire DNA single strand is designed to be divided into several independent regions, each with evenly distributed potential modification sites. These potential modification sites can be any complementary base sites, such as CG fixation sites. Simultaneously, the DNA sequence is rigorously designed to ensure that large-scale complementarity does not occur between long DNA strands, avoiding interference from self-folding and secondary structure formation during modification and sequencing. The subsequence length and the number of modification sites can be flexibly adjusted according to storage capacity and sequencing length, with precise control over the location and distribution of modification sites achieved through chemical synthesis or primer design.

[0044] like Figure 3 The image shows the PAGE results of the DNA template carrying information. PAGE stands for polyacrylamide gel electrophoresis, a method in molecular biology used to detect the purity, integrity, and molecular weight of DNA fragments, and to verify the quality of the prepared DNA storage template. The bands in the image are the target bands of the DNA template after electrophoretic separation. The bands are single, clear, without tailing, extraneous bands, or diffusion. This result directly proves that the DNA template designed and prepared in this embodiment has extremely high purity, intact structure, no degradation, no sequence errors, and no non-specific hybridization. It fully meets the design requirements of no large-scale complementarity of long DNA sequences and can be directly used for subsequent modification reactions, coding, and nanopore sequencing, providing a stable and reliable molecular carrier for multi-level coding and concentration control.

[0045] The standardized DNA vector structure facilitates modification operations, concentration control, and sequencing detection. The uniform site distribution avoids mutual interference between modifications, and the design without large-scale complementary sequences ensures the structural stability of the DNA strand, providing a stable and reliable storage medium for multi-level coding and concentration control.

[0046] Furthermore, based on the above embodiments, this embodiment measures the modification ratio of preset modification sites on the DNA strand, including: performing nanopore sequencing on the DNA strand to obtain the electrical signal of the DNA strand; and performing base recognition on the electrical signal to obtain the modification ratio of the preset modification sites.

[0047] Specifically, nanopore sequencing is performed on modified DNA chains. As the DNA strand passes through the nanopore, a specific electrical signal is generated. Each read corresponds to one per-pore signal. The instrument records the methylation probability of each preset modification site in real time, with a value ranging from 0.0 to 1.0, directly corresponding to a modification ratio of 0% to 100%. By acquiring raw, authentic molecular electrical signals, it provides raw data for quantifying modification ratios. Nanopore sequencing offers advantages such as low energy consumption and high throughput, making it suitable for large-scale storage and detection.

[0048] Basecalling was performed using the Oxford Nanopore tool Dorado, converting electrical signals into base sequences. The open-source tool Modkit was then used to process the data, precisely filtering methylation modification information at preset modification sites. Invalid data with low sequencing quality and significant signal interference were removed, and the accurate modification ratios were calculated after retaining valid methylation probability data. Standardized tools enabled precise data processing, significantly improving the accuracy of modification ratio determination by removing interfering data and ensuring the accuracy of subsequent coding mapping.

[0049] Furthermore, based on the above embodiments, after classifying the modification ratio into the corresponding concentration category, this embodiment also includes: analyzing the error distribution characteristics of the modification ratio and screening out error-prone sites; performing RS error correction on the acquired data; if RS error correction fails, performing soft decoding error correction on the error-prone sites and iterating RS error correction to restore the stored information.

[0050] Specifically, experimental errors in DNA modification writing and signal deviations in nanopore sequencing can lead to deviations in the determination of modification ratios, thereby causing coding errors. Therefore, after the modification ratio is categorized into concentration categories, a soft decision-correction decoding operation must be performed, as follows: Analyzing error distribution characteristics and identifying error-prone sites: Extensive experimental verification shows that errors in modification ratios exhibit fixed characteristics, with errors concentrated in regions adjacent to correct concentration categories rather than being randomly distributed. Analyzing the modification ratios of all sites using statistical templates allows for precise identification of error-prone sites prone to classification errors. Targeted identification of high-risk error sites avoids indiscriminate error correction, significantly improving error correction efficiency and accuracy.

[0051] First, conventional RS correction (hard decision correction) is performed on the overall acquired data. If correction is successful, data recovery is completed. If correction fails, soft decoding correction (soft decision decoding) is applied to the selected error-prone sites, utilizing the characteristic that the error distribution is concentrated in the adjacent regions of the correct concentration category. This involves correcting errors based on the probability information of the modification ratio falling into each concentration category, followed by another RS ​​iterative correction. This process continues until the erroneous data is completely corrected or the preset number of iterations is reached. Figure 5 As shown in the quaternary experimental results and accuracy, after processing by this RS iterative error correction and soft decoding error correction scheme, the stored information can be 100% fully recovered without data loss.

[0052] Furthermore, based on the above embodiments, this embodiment performs soft decoding error correction on the error-prone sites, including: using soft decoding error correction to correct the error-prone sites and iteratively performing RS error correction; wherein, the error distribution characteristic is that the errors of the modification ratio are concentrated in the adjacent concentration categories of the correct concentration category.

[0053] Specifically, this embodiment employs a soft decoding error correction method to correct error-prone sites. This involves correcting errors based on the probability information of the modification ratio falling within each concentration category, followed by iterative execution of the RS error correction algorithm. The error distribution characteristic is that errors in the modification ratio are concentrated in concentration categories adjacent to the correct concentration category. If a single soft decoding plus RS error correction fails to fully recover the data, the soft decoding parameters are adjusted and the process iterates again until the erroneous data is completely corrected or the preset number of iterations is reached. Compared to simple RS iterative error correction, this scheme can more fully utilize the probability distribution information of the concentration ratio, further reducing redundancy and improving the error correction success rate.

[0054] Furthermore, based on the above embodiments, this embodiment reads out the information stored as a preset modification site by using the encoded symbol corresponding to the concentration category, including: converting the encoded symbol into at least one information type of image data or text data for output.

[0055] Specifically, after reading out the encoded symbol corresponding to the concentration category, the mapping inversion needs to be completed. According to the preset random mapping rules, the decoded base number is inverted into the original encoded data, and then converted into at least one type of output, such as image data or text data, supporting multi-type data and mixed base storage.

[0056] Text data storage and output: It can store text information such as letters and characters, such as... Figure 4 This feature stores the methylation probabilities at different DNA template sites during Encryption, providing a complete view of the text information storage and reconstruction process. The methylation probability at each site corresponds to a coded symbol, which, when combined, accurately reconstructs the Encrypted text. It supports the secure storage and transmission of highly sensitive text-based data, offering strong encoding concealment.

[0057] Image data storage and output: It can store visual data such as facial images and sports images, and convert coded symbols into pixel data to achieve high-definition image restoration. It expands the storage scenarios for visual data and adapts to the data storage needs of bioinformatics and multimedia.

[0058] This method supports separate or mixed storage of binary, quaternary, and octal data, making it suitable for high-sensitivity data storage and transmission, as well as core areas of bioinformatics. For dual-site storage designs, one bit from either site can be randomly selected as valid data for subsequent processes, enhancing storage flexibility. By comprehensively expanding the invention's application scenarios, it meets diverse data storage needs, combining security, flexibility, and practicality.

[0059] The method of this invention constructs a DNA storage method based on multi-molecular channels, possessing composite coding characteristics and dynamic control capabilities. Through innovative concentration bit encoding, it can process information efficiently, securely, and flexibly. This method deeply integrates the concentration control principles of biological systems with DNA storage technology, demonstrating enormous application potential in fields such as highly sensitive data storage and transmission, and bioinformatics. It provides a convenient channel for interdisciplinary technological integration and powerfully promotes the development and innovation of the entire field. The advantages are as follows: High storage density: By using multi-level coding based on DNA modification concentration, the information carrying potential of molecular abundance is fully utilized, and the storage density increases exponentially with the number of distinguishable concentration categories; High reliability: The synergistic effect of the soft decision error correction decoding scheme effectively reduces the impact of experimental errors and sequencing biases, ensuring high-fidelity data recovery; Low energy consumption and wide applicability: Nanopore sequencing technology provides an efficient and accurate detection method. The system is suitable for multiple fields such as high-sensitivity data storage and transmission, and bioinformatics, and supports the processing of various types of data such as images.

[0060] The DNA storage system provided by the present invention is described below. The DNA storage system described below can be referred to in correspondence with the DNA storage method described above.

[0061] Figure 6 This is a schematic diagram of the DNA storage system provided by the present invention.

[0062] like Figure 6 As shown, this embodiment provides a DNA storage system, including: The measurement module 601 is used to measure the modification ratio of preset modification sites on the DNA strand. The modification ratio is the ratio of DNA molecules modified at the preset modification sites to all DNA molecules. Encoding module 602 is used to divide the range of ratios into multiple concentration categories according to a preset gradient. Each concentration category corresponds to a coding symbol, forming a multi-base coding system. The segmentation module 603 is used to classify the modification ratio into the corresponding concentration category and read out the coded symbol corresponding to the concentration category as the information stored as the preset modification site.

[0063] Figure 7 This is a schematic diagram of the structure of the electronic device provided by the present invention.

[0064] like Figure 7As shown, the electronic device may include a processor 710, a communications interface 720, a memory 730, and a communication bus 740, wherein the processor 710, communications interface 720, and memory 730 communicate with each other via the communication bus 740. The processor 710 can call logical instructions in the memory 730 to execute a DNA storage method, which includes: determining the modification ratio of preset modification sites on the DNA strand, the modification ratio being the ratio of modified DNA molecules at the preset modification sites to all DNA molecules; dividing the range of the ratio into multiple concentration categories according to a preset gradient, each concentration category corresponding to a coding symbol, forming a multi-level coding system; assigning the modification ratio to the corresponding concentration category, and reading the coding symbol corresponding to the concentration category as information stored at the preset modification site.

[0065] Furthermore, the logical instructions in the aforementioned memory 730 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0066] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the DNA storage method provided by the above methods. The method includes: determining the modification ratio of a preset modification site on the DNA strand, wherein the modification ratio is the ratio of modified DNA molecules at the preset modification site to all DNA molecules; dividing the range of the ratio into multiple concentration categories according to a preset gradient, wherein each concentration category corresponds to a coding symbol, forming a multi-level coding system; assigning the modification ratio to the corresponding concentration category, and reading out the coding symbol corresponding to the concentration category as information stored at the preset modification site.

[0067] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the DNA storage method provided by the above methods. The method includes: determining the modification ratio of a preset modification site on the DNA strand, the modification ratio being the ratio of modified DNA molecules at the preset modification site to all DNA molecules; dividing the range of the ratio into multiple concentration categories according to a preset gradient, each concentration category corresponding to a coding symbol, forming a multi-level coding system; assigning the modification ratio to the corresponding concentration category, and reading out the coding symbol corresponding to the concentration category as information stored at the preset modification site.

[0068] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0069] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for storing DNA, characterized in that, include: The modification ratio of preset modification sites on the DNA strand is determined, wherein the modification ratio is the ratio of DNA molecules modified at the preset modification sites to all DNA molecules. The range of the ratio is divided into multiple concentration categories according to a preset gradient, and each concentration category corresponds to a coding symbol, forming a multi-base coding system; The modification ratio is assigned to the corresponding concentration category, and the encoded symbol corresponding to the concentration category is read out as the information stored at the preset modification site.

2. The DNA storage method according to claim 1, characterized in that, The range of the ratio is divided into multiple concentration categories according to a preset gradient, including: The range of the ratio is divided into N concentration categories, where N is an integer greater than or equal to 2. Each concentration category corresponds to a different coding symbol, forming an N-ary coding system. When N=2, the modification ratio of 0% is classified as the first concentration category, corresponding to the code symbol 0; the modification ratio of 100% is classified as the second concentration category, corresponding to the code symbol 1. Alternatively, when N=4, the modification ratios of 0%, 33.3%, 66.6%, and 100% are divided into four concentration categories, corresponding to the coding symbols 0, 1, 2, and 3 respectively; Alternatively, when N=8, the modification ratios of 0%, 14.3%, 28.6%, 42.9%, 57.1%, 71.4%, 85.7%, and 100% are divided into eight concentration categories, corresponding to the coding symbols 0 to 7 respectively.

3. The DNA storage method according to claim 1, characterized in that, The modification at the preset modification site adopts at least one of the following methods: methylation, phosphorylation, carboxylation, or thiolation.

4. The DNA storage method according to claim 3, characterized in that, The methylation modification is performed using 5-methylcytosine modification, and the preset modification site is selected from the CpG dinucleotide site.

5. The DNA storage method according to claim 1, characterized in that, The DNA chain consists of multiple sub-sequences of predetermined length, with a predetermined number of predetermined modification sites distributed on each sub-sequence.

6. The DNA storage method according to claim 1, characterized in that, The determination of the modification ratio of preset modification sites on the DNA strand includes: Nanopore sequencing was performed on the DNA strand to obtain the electrical signal of the DNA strand; The electrical signal is subjected to base identification to obtain the modification ratio of the preset modification sites.

7. The DNA storage method according to claim 1, characterized in that, After classifying the modification ratio into the corresponding concentration category, the method further includes: Analyze the error distribution characteristics of the modified ratios and screen out error-prone sites; RS error correction is performed on the acquired data. If RS error correction fails, soft decoding error correction is performed on the error-prone points, and RS error correction is iterated to restore the stored information.

8. The DNA storage method according to claim 7, characterized in that, The step of performing software decoding error correction on the error-prone points includes: The error-prone points are corrected using a software decoding error correction method, and RS error correction is performed iteratively. The error distribution feature is that the errors in the modification ratio are concentrated in the adjacent concentration categories of the correct concentration category.

9. The DNA storage method according to claim 1, characterized in that, The step of reading out the information stored as the preset modification site, corresponding to the coded symbol of the concentration category, includes: The encoded symbols are converted into at least one information type, either image data or text data, and output.

10. A DNA storage system, characterized in that, include: The measurement module is used to measure the modification ratio of preset modification sites on the DNA strand, wherein the modification ratio is the ratio of DNA molecules modified at the preset modification sites to all DNA molecules. The encoding module is used to divide the range of the ratio into multiple concentration categories according to a preset gradient, with each concentration category corresponding to an encoding symbol, forming a multi-base encoding system; The segmentation module assigns the modification ratio to the corresponding concentration category and reads out the encoded symbol corresponding to the concentration category as the information stored at the preset modification site.

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