  Deoxyribonucleic Acid (DNA), with its high density and long durability, is a
promising storage medium for long-term archival storage and has attracted much
attention. Several studies have verified the feasibility of using DNA for
archival storage with a small amount of data. However, the achievable storage
capacity of DNA as archival storage has not been comprehensively investigated
yet. Theoretically, the DNA storage density is about 1 exabyte/mm3 (109
GB/mm3). However, according to our investigation, DNA storage tube capacity
based on the current synthesizing and sequencing technologies is only at
hundreds of Gigabytes due to the limitation of multiple bio and technology
constraints. This paper identifies and investigates the critical factors
affecting the single DNA tube capacity for archival storage. Finally, we
suggest several promising directions to overcome the limitations and enhance
DNA storage capacity.
