Blood Issues

If offered a choice, always take a breath, rather than a blood test. Blood tests tend to be more reliable, but you can still attack and win a DUI case with a blood test.

These are just some of the areas our Glendale attorneys look at when defending a DUI case that involves blood issues resulting from a blood test:

The Blood Draw

QUALIFICATIONS / CERTIFICATION of the person who drew the Blood. In Arizona see Nihiser. (Only individuals who have been trained in the practice of blood withdrawal may draw blood for BAC testing. State v. Nihiser, 191 Ariz.199, 953 P.2d 1252, (App. Div. 2 1997) citing State v. Tocco, 156 Ariz. 116,119-20, 750 P.2d 874, 877-78 (1988).

SWAB - What was used to cleanse the site of venipuncture? Hospitals often use isopropyl alcohol to cleans cite of blood draw, which can contaminate blood sample. Also, if NIK kit used, ask in discovery for content of forensic swab. If betadine, EtOH is an "inert" ingredient.

What Was Tested? Whole Blood Or Plasma?

Whole blood is composed of cellular material, plasma and fibrinogen (clotting agent). Hospitals test serum or plasma. Medical blood draws are primarily concerned as to whether alcohol is on board. Forensic blood draw is concerned with precise concentration. Testing plasma or serum is less messy than testing whole blood, but there are problems when testing plasma. When you centrifuge the blood sample, you take the solid, cellular material out, but you leave the same amount of EtOH in a lesser volume of liquid. This process artificially raises the concentration of alcohol in the liquid-D's alcohol concentration has just been inflated. Hospitals test serum or plasma but report it as "blood alcohol." Hospital tests will be higher than forensic tests. Serum is plasma less the fibrinogen. They get serum by letting the blood clot. When the blood clots a clear liquid forms over the blood. That's serum. For our purposes, the difference between serum EtOH concentration and plasma EtOH concentration is negligible. But, if it is not a whole blood analysis, if it is serum or plasma, we are going to get an erroneously high EtOH reading. Usually agreed to average about 16% higher than whole blood analysis. Fitzgerald's 1999 supplement cites three studies showing the serum alcohol versus whole blood alcohol differential to be as high as 20%.

Lawrence Taylor's Drunk Driving Defense (5th Ed.) references the differential to be as high as 30%. Bottom line is this: You must ask the lab tech, "Did you centrifuge the blood?" "Did you test serum/plasma or whole blood?"


Hematocrit is the percentage of your whole blood that is made up of cellular material. If someone has a Hematocrit of 47, we are saying that 47% of their blood is made up of cellular material, and the remaining 53% is plasma (mostly water). The normal range for a male is 47%- slightly lower for a female.

What happens if D had a Hematocrit of 60; i.e., he had a higher percentage of cellular material, and they tested plasma? You're going to get a higher BAC because you have a lesser volume of liquid. Alcohol will always gravitate toward the liquid. So, you have a higher BAC result with higher Hematocrit. The higher EtOH concentration results from the alcohol being contained in a lower volume of liquid (the plasma). Note also that trauma can result in a lower Hematocrit. Hospital records will usually show Hematocrit.

IV Before Blood Draw (Cross Reference Lactated Ringers)

Wouldn't more liquid tend to dilute the EtOH and give D a lower BAC reading because we are increasing the volume of liquid because of the IV? No! Alcohol tends to follow water in the blood. When you consume alcohol, you don't just have alcohol in your blood stream. You have alcohol in your body tissues as well. If you increase the liquid (as a result of an IV), that liquid tends to pull more alcohol out of the tissue and artificially increases D's BAC. So, an IV put into a person before a blood draw will artificially raise the BAC.

Blood Test Kits

Expiration Date

Blood test kits (formerly Becton-Dickinson) now manufactured by NIK Public Safety Inc. THESE KITS HAVE EXPIRATION DATES. This pertains to the period that the vacuum in the vacutainer tube is warranted. Each tube contains a preservative and an anticoagulant (Discussed infra). A precise vacuum exists in the vacutainer tube to assure a precise amount of blood will be drawn and be mixed with these chemicals in precise ratio. If there is too much chemical and not enough blood, this can affect your test result because preservative and anticoagulant are salting out agents. (Discussed infra).

Also, if vacutainer leaks, micro organisms from the room air can enter the sample. Fermentation is a result of combining blood with micro organisms. EtOH is a byproduct of fermentation. There is no way to distinguish between alcohol consumed by a subject and alcohol created by fermentation.

John Tarantino's DWI Journal of Law and Science, suggests that we inquire as to whether the lab did a bacteriological assay of the D's blood to rule out the production of a "Post Collection Forensic Artifact." In other words, we want to ask the lab mope, "Did the lab test the blood for bacteriological contamination?"

Chemicals in Vacutainer Tube

Each vacutainer kit is intended to take 10 ml of blood. Each kit contains two chemicals: 100 mg of sodium fluoride (a preservative to prevent fermentation and neo-production of EtOH) and 20 mg of potassium oxalate (an anticoagulant designed to prevent clotting of the blood).

The first question you must ask is, "Were these chemicals in the vacutainer tubes?" These chemicals are critical to an accurate test result. On cross-examination, you want to ask the cop and the phlebotomist if he or she checked the vacutainer tubes to confirm that powder was in the tubes.

Where was the blood kit kept prior to the blood draw? In the trunk of the police car? For how long and under what conditions?

Instructions in Blood Kit

NIK kits have two sets of instructions. One for the person drawing the blood and one for the cop. One of the instructions pertains to MIXING of the blood immediately after the blood draw. After the blood is in the vacutainer, the person drawing the blood is to invert the tube 5 times. Then, the cop is to invert each tube 20 times. Tubes must not be shaken. Purpose of inversion ritual is to assure proper mixing of blood and chemicals in tubes.

Chain of Custody

Is there a "secure refrigerator" with a log book. A break in the chain of custody usually goes to weight and not admissibility. Some cases (New York) held contra in extremely outrageous situations.

Gas Chromatography

Distinguish - There are two types of G/C in blood analysis-direct measurement of the blood sample and measurement of the gas in the head space above the liquid.

Gas Chromatography (G/C) is a method of (a) identifying a substance and (b) determining the concentration of that substance. The process is both qualitative {what is it?) and quantitative (how much is there?).

Generally, a G/C consists of a steel column filled with a granular substance (e.g., sand). That granular substance is coated with a nonvolatile liquid chemical. Nonvolatile means the chemical won't combine with what you are putting through the column.

We inject the substance that we wish to test into the column. The column is sitting inside of an oven. The oven is keeping the column at a constant temperature. As soon as we introduce our blood sample, it is immediately vaporized. This vapor starts going through the column. The vapor of our test sample is carried through the column on a stream of inert gas, usually hydrogen or helium. The stream of gas is set at a specific rate of flow that goes through the column carrying our vapor of the sample we are testing.

The internal standard (the N-Propel alcohol) is injected and mixed with the D's blood. Then, a sample of this mixture is introduced into the chromatograph. Usually the amount introduced is between one and ten microliters of solution, ideally three microliters of solution. This is a very small amount of chemical being tested. An eyedropper yields 50 microliters of liquid. N-Propel alcohol is being introduced into the chromatograph and vaporized. The column is 1/8th of an inch in diameter.

Salting Out Chemical

In addition to the N-Propel alcohol, the lab adds a chemical to the mixture to help the alcohol get out of the liquid and into the vapor. The higher the concentration of salting out agent, the more alcohol in the vapor. Too much salting out agent will erroneously put too much alcohol in the vapor than should be in relation to the alcohol in the liquid. This brings us back to our chemicals in the vacutainer tubes. Sodium fluoride and potassium oxalate are salting out agents.

Gas Head Space Chromatography

In gas chromatography you are actually testing D's blood. In gas head space chromatography, you are testing the gas or vapor above the liquid-not the liquid itself. The head space is the space above the liquid. The alcohol evaporates (at a rate of speed determined by temperature) from the liquid to the gas in the head space above the liquid. The alcohol will evaporate until it reaches the point of equilibrium. Equilibrium is determined by temperature. The higher the temperature, the more alcohol in the gas above the liquid.

By way of analogy, this is why core body temperature variation and expired breath variation can artificially inflate a breath test reading. Breath testing is based on the relationship between alcohol in the blood and alcohol percolating from the blood into the vapor in the lungs. The assumption underlying breath testing is that whatever alcohol is present in one ml of breath, 2100 times that amount will be present in one ml of blood. Dr. Hlastala debunks this assumption.

This same theory underlies gas head space chromatography. With this process, the lab makes up the same mixture of the blood plus the internal standard. They heat the sample and draw off the vapor for analysis. Then the vapor is injected into the chromatograph. How do we know that there is a relationship between the alcohol in this vapor and the actual alcohol in the blood? Now, we get into all of the considerations regarding Henry's Law. How is the temperature regulated? What was the temperature? What is the relationship between the EtOH in the head space and the EtOH in the blood? The primary disadvantage to head space chromatography is the partition ratio and the effect of temperature and pressure.

Themes for Case

  • They didn't check to confirm the chemicals were there.
  • They didn't do the things necessary to assure a proper mix between the blood and the chemicals in the vacutainer tubes.
  • Were the chemicals in tubes in the proper concentration?
  • They didn't look. They didn't know. They didn't care.

Potassium Oxalate - The Anticoagulant

20 mg of potassium oxalate is used to prevent blood from clotting. Remember, if blood clots, the EtOH goes to the liquid and increases BAC reading. Potassium oxalate combines with calcium ions in the blood to prevent formation of flambin. Flambin is a clotting element. If blood clots, we are going to get a higher EtOH concentration in the liquid above the clot. Any clotting is going to raise the BAC. After the blood draw, but prior to analysis, you can do a test to determine if the anticoagulant is present. That test is called "Ion Chromatography."

ASK THE LAB TECH: "Can you do it?" "Did you do it?"

  • We are establishing a theory that the lab just didn't care to perform the tests necessary to assure a higher than accurate test result. What if the lab guy says, "Well, if the blood clotted, I would have seen it upon visual inspection." WRONG! Blood can form micro clots that can't be seen upon visual inspection.

Sodium Fluoride - The Preservative

The 100 mg of sodium fluoride is a preservative to prevent formation of EtOH by fermentation of the blood. Fermentation of blood can have a dramatic impact upon EtOH concentration. A blood sample with no alcohol can generate .25% BAC or higher as it decays. This "neo-genesis" type of alcohol cannot be distinguished from the alcohol they are testing for. Refrigeration will slow down the fermentation process, but not prevent, fermentation and the production of alcohol.

Where do the preservative and anticoagulant come from?

  • NIK purchases the chemicals commercially, in bulk. Then, NIK mixes them in bulk. A measured amount of each chemical is dropped into the vacutainer tube as it goes down the assembly line. NIK does not sample the vacutainer tubes once the chemical is in it. The presence, and amount, of chemical is critical. If the tubes aren't tested, how do you know them chemicals are there and there in the proper concentration?

Questions for Lab Technician

  • You've never tested a vacutainer tube to determine if the proper concentration of chemicals were present?
  • You couldn't be bothered to confirm that just one of the tubes had the proper amount of chemicals in it?

A.W. Jones is on record that, in order to prevent fermentation, you need 100 mg of sodium fluoride in the tube.

Interesting Demonstrative: Compare state's dark, gunky blood with bright red blood from a fresh blood draw. (Perhaps client will volunteer for a de novo blood draw)

Machine Error

Like the IR 5000, Intoxilyzer or any other breath test machine, the G/C has a margin of error under our administrative regs. Most crime labs in Maricopa County claim to be accurate to within 3-5%. In fact, their actual accuracy can be much less precise.


The key to attacking the chromatograph is the standards. The accuracy of the process depends on what you tell the chromatograph the standards are. The lab tells it what a .10 looks like; what a .20 looks like, etc. Everything is a comparison. If the standards are off, the test is garbage. Where do the standards come from? Who prepared the standards? If the standards are commercially purchased, did the lab verify the standards? Did they test the standards on that chromatograph? The integrity of the whole process is determined by the accuracy of those standards. Did the low bidder get the contract for those standards? Chromatography rides on the validity of the standards that are used to calibrate the chromatograph.