Research biologics are widely used in biomedical research． Contaminations of research biologics with infectious agents are risk factors for vivarium biosecurity and may compromise the in vivo research． Therefore，precautionary screening on the biologics should be perform，before inoculating those biologic materials into rodents，in order to confirm that they are free of rodent infectious agents． Due to scientific，technical and economic constraints，it is not feasible to screen for all rodent infectious organisms． This overview was a proactive attempt，based upon the current literature，personal experience and expert opinion，in trying to describe how to set up a strategy for microbiologic contamination screening and the rationale for selecting certain infectious agent for testing． The impact of those agents on research，vivarium biosecurity，and occupational health and safety，is also summarized．