Application of Free and Encapsulated DNA Tracers in Surface Water Studies in Lithuanian Climatic Conditions

The applicability of free and encapsulated DNA as tracers in surface water studies in Lithuanian climatic conditions was evaluated. Tracer DNA synthesis and analysis were performed using real-time polymerase chain reaction (RT-PCR). Alginate and chitosan were used to obtain the microcapsules with DNA, and their sizes were determined using an atomic force microscopy. The Murlė stream in the city of Vilnius was chosen for field experiments using the prepared tracers. It was found that both types of tracers may be applied to surface water studies, but the relative concentration recovery of encapsulated DNA tracers is 3-6 times higher than that of free DNA tracers. It was concluded that the alginate/chitosan capsules protect DNA from the sandy layer in Murlė stream, direct UV exposure and other environmental factors that could degrade DNA. To our knowledge, this is the first report about free and encapsulated DNA tracer application in surface water studies in Lithuania.