The need for precautions when experimenting with cells in culture depends upon the source and nature of the biological material, the experimental procedure, and the laboratory/containment conditions. Since every situation is different, the risks need to be identified and appropriate precautions need to be taken before any work begins.
More information on risk assessment and precautions can be found in the Center for Disease Control (CDC) publication Biosafety in Microbiological and Biomedical Laboratories, (BMBL) 5th Edition.29 The text of this publication is available in its entirety online. Information on agent risk assessment and a description of the four biosafety levels can be found in this publication.
ATCC assigns a biosafety level (BSL) to each cell line for purposes of packaging for safe shipment. When a cell line is known to contain an etiologic agent, ATCC classification is at least comparable to the BSL assigned to the agent by the CDC and in some cases the ATCC designation is more restrictive. ATCC follows federal biosafety guidelines and takes several factors into consideration when assessing potential hazard.
Biosafety Level 1
- Cell lines with animal origin not included under Biosafety Level 2
Biosafety Level 2
- Cell lines that harbor mycoplasma or any other BSL 2 agent (See: NOTE)
- Cell lines exposed to or transformed by a primate oncogenic virus
- Primate cell lines that contain viruses
- Cell lines carrying a part of certain viral genomes, even if whole virus is not released from the cell30
Some patent cell lines at ATCC are known to be contaminated with mycoplasma and are noted as such in the catalog.
As the recipient of a cell line, take into account not only the nature of the material but also the manipulations employed during its handling when assessing the potential laboratory risk. For example, procedures involving large volumes of cell lines that contain HIV or that include manipulation of HIV in high concentration should be conducted under BSL 3 conditions.29
It is not possible to screen cell lines for the presence of every agent. For added precaution, ATCC handles all cell lines under BSL 2 practices, even those classified as BSL 1. It is prudent to treat all mammalian cell lines as potentially hazardous.