A Novel Microfluidic Strategy for DNA Data Random Access Via Droplet Digital PCR

Here we present a novel strategy for DNA data random access by combining droplet digital polymerase chain reaction (ddPCR) with on-chip fluorescence-based sorting. Standard PCR technique has been widely used for random access in DNA data storage, i.e., using specific primer sequences as file indexes. However, such amplification carried out in bulk solutions suffers from issues in both sensitivity (for retrieving rare data) and selectivity (for file accessing accuracy) [1]. In this work, ddPCR was implemented during data accessing process to replace bulk amplification and DNA sequences encoding different files were separated into droplet partitions. After amplification, those positive droplets containing sequences corresponding to the requested files are then sorted on-chip using dielectrophoresis. Once these droplets are collected, the target file can be retrieved through Next-Generation Sequencing (NGS) and data decoding. Our strategy is anticipated to significantly enhance the selectivity and sensitivity of DNA data storage retrieval while mitigating the adverse effects associated with bulk amplification.