| | Re: How to prevent DNA cross-contamination in DNA extraction????
In fact, ethanol is NOT the best to prevent cross-contamination but it works fine to clean small spills (like small blood stains or drops). I believe is like this for 70% ethanol: the larger the contamination the lesser its effectiveness.
As I told you before, ethanol has worked fine for me. Still, if you are not completely sure you can use negative controls for DNA extraction, this is, using sterile water instead of sample (blood in your case), to confirm that there are not cross-contamination.