Preparation of the nematode-trapping fungus, Arthrobotrys oligospora, for scanning electron microscopy by freeze substitution.

A freeze-substitution technique for preparing fungal specimens for scanning electron microscopy is described. This involves cryofixation in liquid nitrogen, freeze substitution in methanol at -20 degrees C and critical-point drying. The trapping complexes and conidiophores of the nematophagous fungus Arthrobotrys oligospora are well preserved and retain their normal three-dimensional arrangement.