The prosecution will use several people to provide evidence and testimony in Drug DUI cases. They will use the arresting officer who will lay the foundation for the upcoming blood test. Then they may call on the phlebotomist who took the blood test and someone from the lab to testify.
The people who work in the labs are often busy and don’t particularly like to come in and testify, so cases often get continued due to the unavailability of many players on the prosecution side.