Test Characteristics of Acridine Orange, Gram, and May-Grünwald-Giemsa Stains for Enumeration of Intracellular Organisms in Bronchoalveolar Lavage Fluid

For enumeration of intracellular organisms (ICO) in bronchoalveolar lavage fluid samples, the May-Grünwald-Giemsa (MGG) stain displayed higher interobserver agreement than the acridine orange and Gram stains. The MGG stain offered a reliable enumeration of ICO when 200 cells were counted by one observer.