Determination of dissolved deoxyribonucleic acid concentration in lake water

In this paper we d ~s c u s s the sultablllty of the cetyltrimethylammonium bromlde (CTAB) precipitation method for the determination of dissolved DNA (dDNA) In lake water. Factors affecting dDNA recovery from the precipitate and further DAPI fluorometr~c assay were also examined. The proposed method was particularly suitable for routine determination of dDNA concentration in low and moderately eutrophicated freshivater environments The detection 11m1t of the method v a n e d from 1.5 pg dDNA 1. ' for mesotrophlc waters to 2 5 pg dDNA I-' for e u t r o p h ~c lakes. Preliminary observatlons on the concentration of dDNA in the surface water of 8 southern German lakes showed that dDNA concentrations were generally related to their trophic status and varied between 2.5 and 46.0 pg I-' in mesotrophlc and from 11.5 to 72 pg I-' in eutrophlc waters KEY WORDS. Dissolved D N A . Lake w a t e r . CTAB . DAPI