Spontaneous Protoplast Fusion - During isolation of protoplasts for culture, when enzymatic degradation of cell walls is affected, some of the protoplasts, lying in close proximity, may undergo fusion to produce homokaryons or homokaryocytes, each with 2-40 nuclei. The occurrence of multinucleate fusion bodies is more frequent, when protoplasts are prepared from actively dividing cells.

This spontaneous fusion, however, is strictly intraspecific. However, spontaneous fusion of protoplasts can also be induced by bringing protoplasts into intimate contact through micromanipulators or micropipettes.