title: Cryopreservation of viable Giardia intestinalis trophozoites.
abstract: A technique is described for the cryopreservation of Giardia intestinalis trophozoites. The most satisfactory results were obtained when organisms were preserved with either 7.5 or 10% dimethyl sulphoxide (Me2SO) and cooled using a liquid nitrogen controlled freezer. Under these conditions more than 70% of organisms were motile after thawing. Lower recovery rates were obtained using glycerol as the cryopreservant or when samples were placed directly into a -70 degrees C refrigerator to cool. Cultures were successfully re-established from material cooled under controlled conditions using either 7.5% Me2SO or glycerol as the cryopreservant. However, the former had an initial generation time of 12.0 hours compared to 24.5 hours for the latter.
mesh_terms: D000818:Animals; D004121:Dimethyl Sulfoxide; D005615:Freezing; D005872:Giardia / Q000254:growth & development / Q000502:physiology; D005990:Glycerol; D009068:Movement; D011309:Preservation, Biological / Q000379:methods*; D013997:Time Factors
chemical_list: D005990:Glycerol; D004121:Dimethyl Sulfoxide