Moin Patrizia

Although i did not work with this specific kit yet, i would strongly recommend that you carefully evaluate the overall extraction efficiency of your target with spiking experiments. From my experience working with food and environmental samples there are huge differences in extraction efficiency depending on the matrix, background flora and especially your target and sometimes you have to test different kits to find the best one for your application.

My students got the same issues and we are struggling for a month..... still got no answer.

Thanks for the comments. I still have no idea if really the transition from MOBIO to QIAGEN caused this.... We used to obtain higher DNA yields with MOBIO for the same sample (seawater). We also isolated lots of bacteria from the seawater. 

I only noticed the difference between the kits, a thickness of the silica resin..... It was thin before. 

After extract your gDNA, is it necessary use RNase? if yes, what is the best protocol for using?

Hello Patrizia, thanks for your answer. Do you have the protocol for sodium acetate? Because my sample are quite dirty.