Fungus Nuclei in the Diagnosis of Mycoses

SUMMARY

The morphologic integrity of the fungus nucleus is lost in histologic preparations, unless all stages of fixation, dehydration, infiltration and staining are carefully conducted. Fixation with a modification of Bouin's fixative, dehydration and infiltration by slow and graded steps and staining with Heidenhain's iron-alum haematoxylin demonstrate small nuclei in the tissue phases of some pathogens of man with a minimum of apparent distortion and shrinkage.

Coccidioides, Blastomyces and Paracoccidioides are multinucleate. Histoplasma and Cryptococcus are uninucleate. The nuclei of these fungi are characteristic of those described and illustrated in many other fungi and consist of a delicate nuclear membrane, a vacuolated nucleoplasm and a densely stained single nucleus.