Hi, I extracted samples DNA from marine sediments (from surface to 30 cm depth). Samples were taken on a ship and were directly stored at -80. The sediments were manually grinded in liquid nitrogen and the DNA was extracted using a Qiagen powersoil DNA kit. i have thereafter run an electrophoresis gel to check the DNA. I am getting these bright gradients bands and would like to know your opinion on the likely of their origin (natural DNA degradation in sediments? manipulation errors?).

I am planning to use this DNA to amplify it and to do amplicon sequencing. I would guess DNA purfication is a necessity in my case?

Thanks!