Fermentation in CA DUI Blood Test Samples:
Problems With the CA DUI Blood Test: Fermentation and Contamination.
The first problem with blood testing for alcohol is that it’s impossible to tell how much alcohol was present at the time of the blood draw and how much alcohol was created by later fermentation of the sugars in blood by microorganisms. In other words, the microorganisms naturally present in the blood begin to produce alcohol in the sample.
Chemical Model of DUI Blood Test Fermentation
What happens while the blood is stored is that the glucose (sugar) naturally occurring in the blood is converted by microorganisms (Candid Albicans and Saccharomyces Ellipsoideus, among others), through the process of fermentation, to alcohol. Fermentation is a fancy name for eating. These microorganisms eat the sugar, remove energy from the sugar and leave carbon dioxide and alcohol as waste products. Studies show that over .20% BAC can be produced in improperly stored samples.
When the blood is drawn, if it is not done by accepted medical practices, the sample can be contaminated. Simply using a non-alcohol sterilizing agent on the area where the blood is drawn is not enough to prevent contamination. Improperly sterilizing the area can cause contamination.
Even if the area of the blood draw is properly sterilized, microorganisms present in the blood can cause fermentation.
A preservative/anti-coagulant is supposedly added to blood drawn by the cops, but no lab in California tests for the presence of preservative/anti-coagulant. So we never know if it was present in the proper amount or if it was properly distributed in the sample. In fact, breweries add the preservative supposedly used by law enforcement to their beer to ensure that only the right microorganism ferments their beer.
Once collected, the sample is supposed to be stored at or near freezing (32 F) and the test is supposed to be performed with 7 days to minimize fermentation. This is rarely, if ever, done.The sample is usually stored for 4 weeks, unrefrigerated.
Another problem is that the sample can never be proven by the State to contain only alcohol present before the blood was taken from the body. When the chromatograms of the blood tests are reviewed it is often shown that acetaldehyde is present. Acetaldehyde is a precursor to alcohol produced in the microorganism fermentation process after the blood is taken.
In addition to the fermentation that takes place post-draw, there can also be further contamination that can be seen in the peaks in chromatograms. A proper peak is symmetrical and shows only alcohol. An improper peak is broad or has a front or tail that is not symetrical. An improper peak is evidence of contamination in the sample. It means that there is more than one volatile organic compound in the tube at the same time and not only alcohol. So the test reads higher in alcohol than it really is.That means that the State can never prove what the BAC is because the amount that is coming out that is alcohol can never be determined.