Single-stranded DNA (ssDNA): a polymerized chain of deoxyribonucleotides that is not paired with a complementary polymer. Usually formed by denaturing dsDNAplugin-autotooltip__default plugin-autotooltip_bigDouble-stranded DNA (dsDNA): DNA that consists of two complementary strands of ssDNA paired together via hydrogen bonds between the nitrogenous bases G, A, T, and C. with heat or other methods.