Fig. 8

Sizes and branching angles for Mucorales and aspergillus were stained by fluorescence. A and B corresponded to Aspergillus fumigatus; C and D corresponded to Rhizopus arrhizus. Hyphae can artefactually seem to have septae because tissue can fold over itself during processing, which can create artificial lines that can be confused with septations. Similarly, the historically described 90° branching angle of Mucorales in tissue, versus 45° branching angle of septate moulds, can be difficult to identify in tissue due to interstitial pressures exerted on the fungi by the tissue and alterations in tissue architecture during processing. Thus the wider and irregular (ribbon-like) nature of the hyphae are more reliable distinguishing characteristics than septations and angle of branching [4]