The diagnosis of PCP traditionally relied on microscopic examination of sputum or bronchoalveolar lavage (BAL) fluid. However, these methods can be insensitive. The use of [PCR](https://) to detect Pneumocystis DNA has revolutionized the diagnostic landscape. PCR offers high sensitivity and can detect low levels of the organism that might be missed by microscopy. Other diagnostic tools include direct fluorescence antibody (DFA) staining and serological tests.
