User GuidesSnapGene User Guide Single Stranded SequencesConvert Between Single-Stranded and Double-Stranded Formats

Convert Between Single-Stranded and Double-Stranded Formats

How do I convert DNA sequences between single-stranded and double-stranded formats?

SnapGene 5.2 and later allow creation, import, and manipulation of single-stranded DNA (ssDNA) sequences.

Open or Import a DNA Sequence

Open or import a DNA sequence. In this example, the genome of Parvovirus H1, accession number X01457.1, is imported from NCBI incorrectly as a double-stranded DNA (dsDNA) sequence.

Parvovirus H1 is a single-stranded DNA (ssDNA) virus. The X01457.1 record imports as dsDNA because the NCBI LOCUS record fails to specify that it is ssDNA.

Convert dsDNA to ssDNA

Click menu Actions → Convert to Single-Stranded....

Optional: Reverse Complement the ssDNA Sequence

The Parvovirus H1 genome (minus strand) is the complementary strand to the sequence in the X01457.1 record, so it should also be reverse complemented.

Click menu View → Reverse Complement to obtain the minus strand sequence.

Save the ssDNA Sequence

Save the file. In this example, the 5'-3' ssDNA sequence now correctly represents the Parvovirus H1 ssDNA genome.

Convert ssDNA to dsDNA

Open or import a ssDNA sequence.

Click menu Actions → Convert to Double-Stranded... .

Save the new dsDNA file.