| Test | EF (Aspergillus niger) | GF (Aspergillus fumigatus) | BF (Aspergillus niger) |
| Colour | Slightly brown | Gray | Slightly brown |
| Size | Very large | Large | Very large |
| Microscopy | Pale brown or hyaline conidiophores usually simple, erect, thick walled, with basally foot cells, globose vesicles. Composed of catenulate conidia uniseriate or biseriatephialides on vesicles and phialides acutely tapered at apex. Conidia are single celled, phialosporous, black in mass, minutely echinulate. | Uniseriate pyriform, glubose small in column, smooth or spinose conidia. | Pale brown or hyaline conidiophores usually simple, erect, thick walled, with basally foot cells, globose vesicles. Composed of catenulate conidia uniseriate or biseriatephialides on vesicles and phialides acutely tapered at apex. Conidia are single celled, phialosporous, black in mass, minutely echinulate. |