Animal laboratory cleanroom

1. Animal laboratory level

Class I conventional Animals (CV) refer to common animals whose microorganisms are not subject to special control. It is required to exclude the pathogens of zoonotic diseases and the pathogens of a very small number of severe infectious diseases in laboratory animals. In order to prevent infectious diseases, certain measures should be taken when raising and breeding experimental animals to ensure that the results used for testing are reproducible (that is, no matter different operators, at different times, experiments with animals of the same strain according to the prescribed experimental procedures can all get almost the same results).

Class II clean animals (CL), which require the exclusion of pathogens of zoonotic diseases and major infectious diseases of animals.

Class III special pathogen-free animal (SPF) requires that some specified pathogens be excluded in addition to the second level. The method of sterilization can use high-efficiency air filter sterilization method, ultraviolet sterilization method, triethylene glycol vapor spray method and lithium chloride aqueous solution spray method.

Class IV germ-free animals (GF) or gnorobiotic animal (GN), germ-free animals are not required to carry any microorganisms that can be detected by existing methods. Gnorobiotic animal requires the implantation of one or several known microorganisms on the body of a sterile animal.

2. Requirements for the construction of animal laboratories

There are different requirements for animal room design and management for different levels of experimental animals.

Sterile, known bacteria and animals without special pathogens all need to be raised in a sterile or aseptic environment as possible. This environment is currently commonly referred to as a barrier environment in the international, that is, a barrier is used to separate animals from the surrounding polluted environment just as the fetuses are in the womb of their mothers.

From the perspective of controlling microorganisms, this environment is divided into five categories: isolation system, barrier system, semi-barrier system, open system and laminar flow rack system.

Isolation System: it is a system for raising animals in containers with operating gloves for raising sterile animals and roosting animals. The interior maintains the 100-level cleanliness required by microorganisms, but the room and operator do not need to be considered as a sterile room.
Barrier system: the sterile clean room of about 10,000 to 100,000 grades is used as a breeding room, which is mainly used for long-term breeding and reproduction of animals without special pathogens. Strict management is applied when entering the room, such as showering, changing personal clothes, etc.
Semi-barrier system: relax the management of people and objects in the barrier system when entering and leaving the room, and the plane composition is roughly the same as that of the barrier system.
Laminar Flow Rack System: the cage is placed in clean horizontal laminar flow air. Commonly used in small-scale rearing, but there is a risk of contamination when rearing, operating and handling in general rooms. It can be used as a supplement to semi-barrier.
Open system is a system that does not eliminate pollution to people, objects, air, etc. when entering and leaving the room, but usually requires a certain degree of cleaning management.