DefinitionSynovial fluid analysis is a group of tests that examine joint (synovial) fluid. The tests help diagnose and treat joint-related problems.Alternative NamesJoint fluid analysis; Joint fluid aspirationHow the test is performedA sample of synovial fluid is needed for this test. Synovial fluid is normally a thick, straw-colored liquid found in small amounts in joints, bursae, and tendon sheaths.After the area is cleaned, the health care provider will insert a sterile needle through the skin and into the joint space. Once in the joint, fluid is drawn through the needle into a sterile syringe.The fluid sample is sent to the laboratory. The laboratory technician will check the sample's color and clarity, and then place it under a microscope to check it for red and white blood cells, cry