Dr. Barbera and Dr. Forteza regularly contribute topical Biology articles and news associated with cellular physiology, cellular pathology, cell culture, materials, equipment, methodologies and research. You are encouraged to subscribe via the RSS links to support email alerts to your inbox whenever new content is posted here.
Transporting cells in “DORMANCY” at ambient temperature
Concept of In-Vitro Cell Dormancy: 1. In-Vitro Cell Dormancy is a reversible metabolic state of the cells characteristic because cells avoid apoptosis for long periods of time (from 7 days to 90 days depending on the cell type and environment stability). 2. In-Vitro Cell Dormancy is a reversible metabolic state of the cells, achievable when cells are maintained in HYPOXIA (2% TO 5% O2) and mild HYPOTHERMIA (10OC TO 25OC). 3. In-Vitro Cell Dormancy is a reversible metabolic state of the cells, not a Cell-Cycle phase. In vitro dormant cells lengthen the cell cycle phases resulting in an extended doubling time, but they are not in G0 or “Resting”. 4. In-Vitro Cell Dormancy is a reversible metabolic state of the cells, similar to cryo-preserved but maintained over freezing temperatures. 5. In-Vitro Cell Dormancy is a reversible metabolic state of the cells, with tendency to extend more the G2 phase of the cell cycle. A certain concentration of cells in G2 is common in cultures maintained long periods of time in dormancy.
Use of In-Vitro Cell Dormancy 1. Limited time Cell storage at room temperature. 2. Cell transportation circumventing cryopreservation.
Cell transportation circumventing cryopreservation When cells are cultured in devices with auto-controlled gas diffusion, such as PetakaG3, the natural cell metabolism reduces the partial pressure of the Dissolved Oxygen down to 15 mmHg to 35 mmHg. Just removing from the incubator the cell culture devices the temperature of the culture can drop in a few minutes down to the ambient level (normally in laboratories 22OC or 70OF). This two conditions induce the In-Vitro Cell Dormancy state. The Petakas are capable of maintaining the media osmolarity for more than a month at room temperature even at environment relative humidity of 10%. Therefore the culture can be transported by any means, with certain temperature quenching envelope to avoid sharp temperature variations, safe and easily for 5 to 15 days.
Some cells will go through apoptosis depending on the cell type, the stability of the transportation environment, and the duration of the transportation period. In general the amount of cell loss is predictable for majority of cell lines (see figure 1), however it is recommended testing with any new cell line, never sent in dormant state, keeping the cells dormant in the lab with a daily control of cell survival.
After arrival cell recovery is direct and simple (See video): 1. Put the devices back in the incubator, in horizontal position, at the normal temperature for the specific cell line (37OC for mammalian cells) 2. Maintain in horizontal position in the incubator for 2 hours or maximum overnight 3. Change 90% of the media for the normal cell media used for culturing these cells with the normal additives (FBS, antibiotics, specific growth factors etc.) 4. After confluent, change the media every 24 hours or split the cells in new devices.