Blood Clots Cause Inaccurate Blood Alcohol Tests : A Win for Ramsay Law

Posted On November 28, 2023 Charles Ramsay

In a recent win for our client, a judge overturned a 1-year license revocation on a 0.16 blood alcohol test due to improper blood sample collection procedures!

This case highlights a critical issue with blood alcohol testing: the potential for inaccurate results due to blood clots.

The phlebotomist who drew the blood sample failed to follow standard protocol, which requires inverting the blood tubes slowly 5-6 times after drawing the blood. This step is crucial to mix the tube's anticoagulant and preservative properly.

Without proper mixing, blood clots can form. Blood clots can interfere with the blood alcohol test, leading to either artificially high or low results.


A HUGE problem with the state's crime lab is the lack of specific requirements for blood sample acceptability. They accept any sample that comes in, regardless of its condition.

This lax approach can lead to the analysis of contaminated or improperly handled samples, potentially resulting in inaccurate test results.

When a scientist in the lab analyzes blood samples, blood clots can cause some samples to measure high and others to measure low. However, accurate blood alcohol measurements require a homogeneous blood sample, free from clots or other contaminants.


Fortunately, the judge recognized the flawed collection procedure and its potential impact on the test results. This case serves as a reminder that proper blood sample collection procedures are essential for accurate blood alcohol testing.

If you are facing DWI charges, it’s CRUCIAL to seek a law firm with expertise in the science behind DWI testing.


Accurate blood alcohol testing is essential for upholding the law and protecting the rights of individuals accused of DWI offenses.

At Ramsay Law, we spend a crazy amount of time (and money) getting trained in the science behind DWI testing. We have Minnesota’s only Lawyer-Scientist endorsed by the American Chemical Society.

If you’ve been convicted of a DWI offense, call Ramsay Law. We understand the science AND the law.

We go the extra mile to ensure we get ALL the information from the state before we analyze your case.

Call Ramsay Law today at 651-604-0000.

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