Fig. 1

Standardized bronchoalveolar lavage collection protocol and measurement of return volumes in lung transplant recipients. After initial airway inspection, a bronchoalveolar lavage (BAL) is performed by wedging the bronchoscope in a lung segment, instilling 50 mL of saline followed by aspiration (BAL1), and repeating the instillation of another 50 mL of saline followed by aspiration (BAL2). BAL1 and BAL2 samples are collected into separate containers. 10 mL of each BAL1 and BAL2 were sent to the clinical laboratory. The remaining volume of each of BAL1 and BAL2 was transferred to the research laboratory for further analysis