Potential Problems with DUI Blood Tests By Andrew Mishlove on October 11, 2018

Blood test vialAt Mischlove and Stuckert, our attorneys are experienced in DUI defense. Our DUI attorneys are classified as DUI defense specialists, which is the highest credential that can be obtained by an OWI-DUI defense lawyer. When we take on a case, we will explore all avenues to determine the best defense strategy.

This includes considering DUI blood test problems that could provide our Milwaukee, WI clients with the grounds needed to have their DUI charges minimized or dismissed.

Problems with the Blood Draw

Problems with DUI tests are present from the time of the blood draw. To ensure accurate BAC (blood alcohol concentration) results, protocol must be followed when the blood is drawn.

First, the draw site needs to be cleaned with a non-alcohol sterilizing agent. Without proper sterilization, the blood sample can become contaminated, thus making the test results unreliable.

Second, a specific amount of potassium oxalate must be added to the blood sample. This is an anti-coagulant that prevents the blood from clotting. If there is an insufficient amount of this compound, the liquid to solid ratio of the blood can be impacted, which can result in a higher BAC result than is accurate.

Finally, sodium fluoride needs to be added to the blood test tube. This serves as a preservation agent. As with the potassium oxalate, an improper amount of sodium fluoride could result in a higher BAC result than that which is actually present in the blood.

Improper Storage

Even if a blood test is administered properly, problems can arise if the blood sample is stored improperly. Ideally, a collected blood sample should be tested within seven days. Furthermore, while it is waiting to be tested, blood should be stored at or near freezing temperatures.

Unfortunately, blood tests may not be performed within this time frame. It may take a couple of weeks for blood to be tested, and blood may sit at room temperature while it is in storage. Improper storage can compromise the blood sample and increase the risk of fermentation.


Faulty testing techniques and improper storage both increase the risk of fermentation, which is one of the leading DUI blood test problems. As blood sits, glucose (or sugars) that are present in the blood react with microorganisms and convert it into alcohol.

This process, which is known as fermentation, can happen even faster if there are excessive contaminants in the blood or if the blood is not stored at or near freezing temperatures.

Additionally, the longer that a blood sample sits prior to testing, the more likely that fermentation will increase the BAC, thus showing higher amounts of alcohol than was actually present at the time of the blood draw.

Our attorneys have a thorough understanding of the DUI blood testing process and are able to identify potential problems for our clients. We are the only law firm in the state that can re-analyze computer files created by the state’s blood test machine.

As one of the only law firms with an understanding of blood test chemistry and how to review blood test laboratory records, we can truly offer clients the best chance of avoiding a wrongful DUI conviction as the result of improper DUI blood testing.

Contact Us

At Mishlove and Stuckert, our attorneys have the experience, expertise, and technology necessary to provide clients with the strongest DUI defense strategy. If you are facing DUI charges, contact us at your earliest convenience to learn how our attorneys can be of assistance. Call (414) 332-3499 to set up a personal consultation.

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Andrew Mishlove and Lauren Stuckert

Mishlove and Stuckert, LLC Attorneys at Law

Mishlove & Stuckert, LLC Attorneys at Law has been rated the #1 OWI/DUI law firm in the state by Wisconsin Law Journal Reader Rankings. Our OWI/DUI specialists have been highly rated by organizations including: 

  • Avvo™
  • Super Lawyers
  • Martindale-Hubbell 
  • Better Business Bureau 

To speak with one of our board-certified OWI/DUI defense specialists, request a consultation online or call us at (414) 332-3499.

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