Hydrolysis of DNA and its molecular components in the dry state.

The biochemistry of dry state DNA is of interest to the field of forensic biology. The precise chemical nature of the hydrolytic degradation products of the DNA molecule in the dry state has not been previously investigated in detail. In this study we found that the mechanistic chemistry of DNA hydrolysis appears to be the same for the hydrated and dry states. The thermodynamic parameters are also similar in both states and the activation energies for base hydrolysis are indistinguishable. The principal difference between the two states is the rate at which hydrolytic degradation occurs. The duplex configuration of dry state DNA offers much more protection for the molecule than is offered in single strand and nucleotide species. Single strand breaks of dry state duplex DNA occur with a half life of 24+/-2 days at 65 degrees C and appear to occur in a mechanistic manner. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.