Specific Pathogen Free

Specific Pathogen Free is a term used for laboratory animals that are guaranteed free of particular pathogens. It is always accompanied by a list of the absent pathogens.

Use of SPF animals ensures that specified diseases do not interfere with an experiment. For example, absence of respiratory pathogens such as influenza in desirable when investigating a drug's effect on lung function.

Completely germ free
The animals can be born through a caesarian section then special care taken so the newborn does not acquire infections, such as use of sterile plastic bags with a positive pressure differential.

A disadvantage is that any contact with pathogens will be fatal, since no protective bacterial flora are present. (Not in the intestine, skin or respiratory tract)

SPF
To certify SPF, the population is checked for presence of (antibodies against) the specified pathogens.

Minimal disease status
When by accident some infection does occur, the population is said to have minimal disease status.

Monitoring
The population is regularly checked to ensure the status still holds.

Applications
SPF eggs can be used to make vaccines.