The Galactomannan assay is relatively specific for invasive aspergillosis, and, in the right clinical context, provides adequate evidence of invasive pulmonary disease. 

Most pathogenic fungi have 1–3 beta D glucan in their cell wall and this antigen assay is used for diagnosis of invasive fungal infections. EXCEPTIONS are: Cryptococcus, Zygomycetes (Mucor; Rhizopus) and Blastomyces