You can use them on zombies. If you extract DNA from a zombie who has not already been extracted from in the last day, you get experience points. DNA extractors are cool because you'll never need a new one, they've got unlimited use!
One precaution (though I pretty much ignore it), is that there is a skill that zombies can buy that allows them to track you down if you've extracted DNA from them. I'm not sure how that works since I've never had it, but I hear it's a possibility. Therefore, I suppose one out of every ten zombies you extract from can come find you, if they should choose to do so. And you have no way of knowing if a zombie has this skill, unless the zombie takes some sort of action while you're with it. Like, if it attacked you or spoke to you, it would show up on the side of the screen with a link to their bio and stuff. And there should be a list of what skills they have.
Unfortunately, I don't remember what the skill is called. I am inclined to think it was Scent Fear, but I'm not sure. The skills are listed somewhere on Wikipedia probably.
no subject
One precaution (though I pretty much ignore it), is that there is a skill that zombies can buy that allows them to track you down if you've extracted DNA from them. I'm not sure how that works since I've never had it, but I hear it's a possibility. Therefore, I suppose one out of every ten zombies you extract from can come find you, if they should choose to do so. And you have no way of knowing if a zombie has this skill, unless the zombie takes some sort of action while you're with it. Like, if it attacked you or spoke to you, it would show up on the side of the screen with a link to their bio and stuff. And there should be a list of what skills they have.
Unfortunately, I don't remember what the skill is called. I am inclined to think it was Scent Fear, but I'm not sure. The skills are listed somewhere on Wikipedia probably.
Holy long!