Test Details: Pleural fluid culture is a test that examines a sample of fluid which gets collected in the pleural space to check for presence of infection or to understand the cause of fluid build-up. The pleural space is the area between the lining of the outside of the lungs (pleura) and the wall of the chest. A procedure called thoracentesis is performed to get a sample of pleural fluid. This test is commonly used for the detection of Pneumonia.