Safety and handling considerations
Safety and handling considerations for animal cell culture
Legislation and regulatory guidelines
Safety considerations and biohazards
When working with potentially hazardous material, it is important to be aware of the possible risks associated with both the material and the experimental protocol. All cell cultures are considered a biohazard because of their potential to harbor an infectious agent (e.g., a virus).
The degree of hazard depends on the cells being used and the experimental protocol. Primary cell cultures in particular should be handled carefully as these cultures have a high risk of containing undetected viruses. Although commonly used cell lines are generally assumed to be free of infectious agents, care should still be exercised when working with these cell lines as it is possible that they contain infectious agents, such as latent viruses. Cell cultures used to study specific viruses should be assumed to have the same degree of hazard as the virus under study.
We recommend handling all material as potentially infectious to ensure the safest possible working environment. Work should be performed in an approved laminar flow hood using aseptic technique, and the creation of aerosols should be avoided (see Handling cell cultures). After the work is complete, all waste media and equipment (i.e., used flasks, pipets, etc.) should be disinfected by autoclaving or immersion in a suitable disinfectant according to institutional and regional guidelines.
Handling cell cultures
Aseptic technique and minimization of aerosols
Aseptic technique and the proper use of laboratory equipment are essential when working with cell cultures. Always use sterile equipment and reagents, and wash hands, reagent bottles, and work surfaces with a biocide or 70% ethanol before beginning work.
Creation of aerosols should be avoided — aerosols represent an inhalation hazard, and can potentially lead to cross-contamination between cultures. To avoid aerosols, use TD (to deliver) pipets, and not TC (to contain) pipets; use pipets plugged with cotton; do not mix liquids by rapidly pipetting up and down; do not use excessive force to expel material from pipets; and do not bubble air through liquids with a pipet. Avoid releasing the contents of a pipet from a height into the receiving vessel. Expel liquids as close as possible to the level of liquid of the receiving vessel, or allow the liquid to run down the sides of the vessel.
Proper use of equipment can also help minimize the risk of aerosols. For example, when using a centrifuge, ensure the vessel to be centrifuged is properly sealed, avoid drops of liquid near the top of the vessel, and use centrifuge buckets with caps and sealed centrifuge heads to prevent contamination by aerosols.
Laminar flow hoods
For the most efficient operation, laminar flow hoods should be located in an area of the laboratory where there is minimal disturbance to air currents. Avoid placing laminar flow hoods near doorways, air vents, or locations where there is high activity. Hoods are often placed in dedicated cell culture rooms.
- Keep laminar flow hoods clean, and avoid storing equipment inside the hood.
- Before starting work, disinfect the work surface of the hood as well as the outside of any bottles (e.g., by wiping with 70% ethanol), and then place everything needed for the cell culture procedure in the hood.
- Arrange equipment, pipets, waste containers, and reagent bottles so that used items are not placed near clean items, and avoid passing used items over clean items.
- Place used items (e.g., pipets) in a container inside the hood, and disinfect or seal before removing from the hood.