I think the best is Qiagen for me. There are lots of other options and all work fine. If the load is low, use Qiagen and if it is still very low,then you will have to culture it and extract DNA from the culture instead. However, usually if somebody is actively infected, you will find lots of brucella for your procedure

u can use kit, various DNA extraction kits are available in market like Qiagen.........

fallow the instruction given in respective manual.

important thing is incubation time ...........strictly fallow

all the best

Thanks very for your good helps.