Exposure Control Methods for Prions and PLPs
- As outlined in Biosafety in Microbiological and Biomedical Laboratories (BMBL) 6th Edition,
- Prions from human tissue and human prions propagated in animals can be manipulated at BSL-2 or higher, based on risk assessment.
- Due to concerns about Bovine Spongiform Encephalopathy (BSE) prions infecting humans and cattle, certain circumstances may call for the use of BSL-3 facilities and/or practices.
- All other animal prions may be manipulated at BSL-2 with standard BSL-2 practices. However, when a prion from one species is inoculated into another the resultant infected animal should be treated according to the biosafety guidelines applying to either the source or recipient of the inoculum, whichever is more stringent.
- Based on the risk assessment of the work, some specific in vitro or in vivo work with human PLPs may be manipulated in BSL2, but the work is generally expected to be manipulated at BSL1. Covered in vitro or in vivo activities include, but are not limited to:
- Purification or enrichment of PLPs
- Synthesis, use or production of PLPs in high concentration (relative to natural models)
- Generation or use of mutated PLPs
- Generation or use of fibrillar or misfolded forms of PLPs
- Use of genetically modified animals expressing PLPs
- In vivo animal activities with PLPs
- The principle investigator or lab supervisor must train all workers in specific handling procedures for prions.
- Written Standard Operating Procedures (SOPs) must be available for worker reference.
- Lab access must be limited to trained individuals. If untrained individuals need to enter the lab, they must be accompanied by a trained individual.
- One of the main precautions to be taken when working with prions or PLPs is to avoid puncture of the skin. Therefore, sharps and glass must not be used unless it has been determined that there is no other alternative.
- All work surfaces must be protected with disposable bench covers that are handled as low-level prion or PLP waste.
- All manipulations with prions or human PLPs requiring BSL2 containment must be done in a biological safety cabinet. The biological safety cabinet must be certified annually.
- Follow centrifuge safety procedures. Open centrifuge rotors or safety buckets in a biological safety cabinet.
- Transport of all prion materials or PLPs outside a biological cabinet requires secondary containment.
- All workers must wear the following Personal Protective Equipment (PPE):
- Double gloves
- Lab coat (disposable back closing preferred)
- Face shield (if it is necessary to handle prion material outside the biological cabinet)
- For necropsies on large animals, personnel must wear full-body coverage personal protective equipment: disposable (Tyvek type) coveralls, disposable or washable boots, impermeable nitrile gloves and cut resistant glove on the non-dominant hand, safety glasses, and face shield.
Note: Additional PPE may be recommended based on risk assessment.