qiagen extraction - (Feb/11/2006 )

why in the qiagen DNA extraction is 96-100% ethanol needed in the process. What does it do? Does this step "stick" the DNA to the spin column membrane while filtering the proteins and cellular material through?

I think it washes the salt away from the DNA. The binding buffer helps the DNA stick. The 96-100% ethanol is added to another solution probably making a 70 % ethanol solution thereby assisting the removal of salts when it is washed through the column.