Answer: There are also lots of ways to challenge a blood test result in Wisconsin. For example, when the blood is put into the tube, that there’s not enough anticoagulant in the tube—that is a possible defense. If there’s a problem with the chain of custody, meaning they can’t figure out who delivered the blood to the lab—that would be a defense. If the blood was kept in a hot police car overnight, that could cause fermentation, which is an increase in the blood level—that would be a defense. Another defense in blood test cases is if there’s not enough preservative in the vial as that can cause the blood test results to be askew. There are innumerable defenses based on maintenance problems at the lab with the blood testing protocols. There are many, many defenses to blood test cases in Wisconsin.