title: Use of refrigeration as a practical means to preserve viability of in vitro-cultured IDE8 tick cells.
abstract: In vitro cultivation of the IDE8 cell line, derived from embryonic Ixodes scapularis ticks, constitutes an important system for the study of tick-borne pathogens, as these cells support growth of rickettsial species which are not normally transmitted by this tick. However, since cryopreservation of IDE8 cells is not always successful, there is a need to develop alternative ways to preserve these cells. In the present study, a suspension of IDE8 cells in culture medium was kept under refrigeration at 4 degrees C for up to 60 days. Every 15 days, the suspension was mixed and aliquots were re-cultured in 2-ml tubes, under standardized conditions. In addition, three techniques for cryopreservation, using two different cryoprotectants (DMSO and glycerol), were evaluated. Medium changes were carried out every week and subculturing every 2 weeks. The development of cultures and their respective subcultures, after returning to standard culture temperature, was evaluated by percentage viability and by cellular morphology evaluated in Giemsa-stained cytocentrifuge smears. All cultures and subcultures appeared healthy, showing growth rates comparable to cultures that had not been kept under refrigeration. The results demonstrated that storage under refrigeration at 4 degrees C is an efficient method for preservation of IDE8 cells for up to 60 days and that refrigeration may be preferable to cryopreservation for short-term preservation of IDE8 cells.
authors.affiliation: Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais, CP 567, Belo Horizonte, 30123-970, MG, Brazil.
authors.forename: Camila V
authors.initials: CV
authors.lastname: Bastos
authors.forename: Maria Mercês C
authors.initials: MM
authors.lastname: das Vasconcelos
authors.forename: Múcio Flávio B
authors.initials: MF
authors.lastname: Ribeiro
authors.forename: Lygia M Friche
authors.initials: LM
authors.lastname: Passos
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival; D015925:Cryopreservation; D026863:Ixodidae / Q000166:cytology* / Q000196:embryology; D011309:Preservation, Biological; D012034:Refrigeration