infectious diseases
Microscopy
India ink (colloidal carbon) stain
India ink stain is used to detect mainly Cryptococcosis and other encapsulated fungi in a cell suspension (eg, cerebrospinal fluid sediment). The background field, rather than the organism itself, is stained, making any capsule around the organism visible as a halo. In cerebrospinal fluid, the test is not as sensitive as cryptococcal antigen. Specificity is also limited; leukocytes may appear encapsulated. 