Typically, after a DUI arrest in the state of Florida, the arresting officer will request that you submit to a chemical test, typically a breath sample, but in some instances the officer may request a urine or blood test. The first and main difference between the two tests is the method of testing. A breath test requires you to blow into a breathalyzer, whereas a blood test involves drawing the suspects blood. The breath tests measure the amount of alcohol on your breath, whereas the blood test directly measures the concentration of alcohol within the blood.