The staiblity of cell populations and genetic elements at low temperatures can be affected by the methods used to preserve the material, and by procedures used in handling the material during storage (3).

The intent of this practice is to outline procedures that can minimize the adverse effects of handling biological materials during low temperature preservation and maintenance.

1.1 This practice covers the handling of microorganisms (bacteria, fungi, and protista), viruses, genetic elements (nucleic acids and plasmids), and animal and plant cell tissues (cell lines), during and after freezing and storage at cryogenic temperatures.

1.2 This practice also covers the handling of microorganisms, viruses, and genetic elements in the host cell during and after freeze-drying.

1.3 While this practice does not cover the specific methodology used to freeze and freeze-dry microorganisms and cell lines, the safety aspects of handling microorganisms during freezing and freeze-drying procedures, and during storage at cryogenic temperatures, are covered. Other guidelines must also be adhered to regarding the handling of hazardous materials (2).

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements see Section 6.