When a doctor prescribes a battery of tests for a patient, the tests are almost always done by medical and clinical laboratory technologists. These specialists examine and analyse blood, urine, and other bodily fluids, tissue, and cells. 

They search for bacteria, parasites, and aberrant cells using sophisticated microscopes and other equipment. They also check blood cholesterol levels, as well as type and cross-match blood samples for transfusions. In larger labs, such as those found in many hospitals, technicians typically specialise in blood work, microbiology, or another field. 

The job may also include supervising medical and clinical technicians. A bachelor's degree in medical technology or a life science, as well as an internship, are usually required for this employment. Work can be stressful, especially when you have to complete a hard test precisely in a short amount of time. But it's also pleasant to know that you're giving a doctor the information he or she needs to save a life or cure a condition.