Preservation of Schistosoma mansoni eggs and of infected livers as a source of eggs for the circumoval precipitin test.

Eggs of Schistosoma mansoni and livers with numerous granulomata were preserved at -70 C in 1.7% salt solution plus an equal volume of water-soluble jelly. The eggs were suitable for circumoval tests after at least 1 yr of preservation and the livers supplied adequate eggs for the tests for at least 6 mo after preservation. This procedure may be useful where such storage facilities are available, and the COP test is used for diagnosis.