To be of any relevance for genetic mutation, the products of tautomerisation must survive the mitotic replication of DNA. The replication includes the cleaving of the DNA duplex, caused by the enzyme helicase forcing itself between the two strands of DNA and splitting the base pairs that bind the double helix together. The absence of the A-T tautomer in the equilibrium state of DNA, where the double helix is unperturbed by external forces pulling the structure apart, has been well-studied, but the existence of tautomers on single, separated DNA strands has not been confirmed. Florian and Leszczynski 7 state that the tautomers must outlive the strand separation timescale of ∼100 ps. However, multiple studies have argued that the tautomeric lifetime is much shorter than this timescale. The timescale for which the tautomeric forms of base pairs can exist depends on the stability of the energetic minimum that the tautomeric forms exhibit.