Abstract: This disclosure provides techniques for adding error correction to information in a data store that encodes information as a sequence of bases in polynucleotides. Errors may be introduced through creation of the database (e.g., oligonucleotide synthesis) and/or reading information from the database (e.g., polynucleotide sequencing). Additional polynucleotides added to the database can provide error correction through redundancy. The sequence of polynucleotides that provide error correction may be designed by performing an invertible summary operation on information to be stored in the database. One example of an invertible summary operation is the exclusive or operation (XOR). This disclosure also provides techniques for storing metadata related to organization of a database and structure of information on polynucleotides within the database. Metadata may be encoded in polynucleotides and added to the data store.