Влияние длины молекул и природы среды на фрагментацию ДНК ультразвуком

Abstract

Fragmentation of DNA by ultrasound is the most optimal method of artificial degradation of DNA molecules. It requires no reagents and makes it possible to obtain "pure" DNA samples for further use. However, despite an active usage of ultrasonic fragmentation in studies, a number of issues related to the applicability of mechanically degraded DNA for standard molecular biological operations remain poorly studied. This report presents data on the effect of the size of DNA molecules (on DNA amplicons) and the composition of aqueous solutions on the efficiency of DNA destruction by ultrasound. It has been shown that the rate of DNA fragmentation positively correlates with an increase in the length of molecules. In solutions with high ionic strength, the rate of fragmentation increases dramatically. The presence of organic solvents that do not affect hybridization slightly reduces the rate of ultrasonic destruction. With an increase in the length of DNA molecules, the influence of denaturing agents changes and leads to an increase in the rate of fragmentation. dsDNA molecules smaller than one persistent length (about 150 bp) are not fragmented.