This disclosure describes frameworks and techniques related to the random access of digital data encoded by polynucleotides. Digital data of a data file can be encoded as a series of nucleotides and one or more polynucleotide sequences can be generated that encode the digital data for the data file. The bits of the digital data can be segmented to produce multiple polynucleotide sequences that encode the bits of the digital data with each polynucleotide sequence encoding an individual segment of the digital data. The individual segments can be grouped together and associated with a group identifier. Each data file can be associated with a number of group identifiers and the number of segments in each group can be within a specified range. Primers corresponding to the group identifiers can be used to selectively access the polynucleotides that encode the digital data of a data file.