Background: The processes of destruction and crosslinking of macromolecules occur simultaneously
under the influence of ultraviolet (UV) radiation in synthetic polymers, dry DNA and
their concentrated solutions.
Objective: The effect of UV radiation on calf thymus DNA in dilute solutions subjected to UV- irradiation
was studied in this work.
Method: The calf thymus DNA was studied in dilute solutions using viscometry, absorption spectroscopy
Results: It was shown that at a low concentration of DNA in the buffer solution ([DNA] = 85 μg /
ml) under the influence of UV radiation, the processes of destruction of macromolecules and an increase
in their flexibility predominate, which are accompanied by a gradual decrease in the viscosity
of their solution. In addition, due to the low concentration of the solution, intramolecular crosslinking
of macromolecules predominates, which also reduces their size and, consequently, the viscosity
of the solution.
Conclusion: It was concluded that in dilute DNA solutions, due to the predominance of the processes
of intramolecular crosslinking of macromolecules over intermolecular, only constant processes
of decreasing the sizes of DNA macromolecules occur. As a result, their solubility remains
virtually unchanged during UV irradiation. The described explanations are also confirmed by the results
of absorption spectroscopy and electrophoresis.