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Cytometry

Biosafety Procedures

Overview of Biosafety Procedures

  • Definition: Biosafety procedures are practices and protocols designed to prevent or minimize the exposure of laboratory workers and the environment to potentially infectious materials or biohazards
  • Importance:
    • Protect Laboratory Workers: To prevent infections and other health hazards
    • Prevent Environmental Contamination: To prevent the release of biohazards into the environment
    • Comply with Regulations: To comply with regulatory requirements and accreditation standards
  • Key Components of Biosafety Procedures:
    • Biosafety Categories
    • Personal Protective Equipment (PPE)
    • Specimen Transport and Preparation Precautions
    • Aerosol Control
    • Decontamination

Biosafety Categories (Biosafety Levels - BSLs)

  • Definition: A system for classifying biological agents based on their potential to cause disease and the severity of the disease
  • Purpose:
    • Determine Appropriate Containment: To determine the appropriate level of containment and safety practices for working with different biological agents
    • Protect Laboratory Workers: To protect laboratory workers from exposure to potentially infectious materials
  • Biosafety Levels:
    • Biosafety Level 1 (BSL-1):
      • Agents: Agents that are not known to cause disease in healthy adults
      • Practices: Standard microbiological practices, such as handwashing and use of personal protective equipment (PPE)
      • Facilities: Basic laboratory facilities with standard equipment
      • Example Agents: Non-pathogenic strains of E. coli, Bacillus subtilis
    • Biosafety Level 2 (BSL-2):
      • Agents: Agents that can cause disease in humans but are not typically transmitted through the air
      • Practices: BSL-1 practices, plus limited access, use of biological safety cabinets (BSCs), and appropriate waste disposal
      • Facilities: BSL-1 facilities, plus self-closing doors and eyewash stations
      • Example Agents: HIV, hepatitis B virus, Salmonella, Staphylococcus aureus
    • Biosafety Level 3 (BSL-3):
      • Agents: Agents that can cause serious or potentially lethal disease and can be transmitted through the air
      • Practices: BSL-2 practices, plus controlled access, respiratory protection, and specialized ventilation systems
      • Facilities: BSL-2 facilities, plus sealed windows, filtered air exhaust, and negative air pressure
      • Example Agents: Mycobacterium tuberculosis, Bacillus anthracis, SARS-CoV-2
    • Biosafety Level 4 (BSL-4):
      • Agents: Agents that can cause highly dangerous or lethal disease and for which there are no vaccines or treatments
      • Practices: BSL-3 practices, plus complete isolation of the laboratory worker from the agent
      • Facilities: BSL-3 facilities, plus a separate, sealed building with specialized ventilation and waste management systems
      • Example Agents: Ebola virus, Marburg virus
  • Personnel must have proper training before working in these environments!

Personal Protective Equipment (PPE)

  • Definition: Equipment worn by laboratory workers to protect them from exposure to potentially infectious materials
  • Common Types of PPE:
    • Gloves: Protect hands from contamination
    • Gowns: Protect clothing from contamination
    • Eye Protection (e.g., safety glasses, face shields): Protect eyes from splashes or aerosols
    • Respiratory Protection (e.g., N95 respirators): Protect respiratory system from airborne pathogens
  • Proper Use of PPE:
    • Select the appropriate PPE for the task being performed
    • Inspect PPE for any damage or defects before use
    • Put on PPE in the correct order
    • Remove PPE carefully to avoid contamination
    • Dispose of contaminated PPE properly
  • PPE must be provided to every worker in the laboratory

Specimen Transport and Preparation Precautions

  • Proper Containment: Use leak-proof containers to transport specimens
    • Seal specimens to avoid any leak during the transportation process
  • Appropriate Labeling: Label all specimen containers with the biohazard symbol and the appropriate biosafety level
  • Specimen Preparation in Biological Safety Cabinet (BSC):
    • Preparation involving infectious material must be performed in a BSC

Aerosols

  • Definition: Airborne particles that can carry infectious agents
  • Sources of Aerosols in Flow Cytometry:
    • Cell Sorting: High-pressure droplet formation can generate aerosols
    • Pipetting: Forceful pipetting can generate aerosols
    • Centrifugation: Improperly sealed centrifuge tubes can release aerosols
    • Opening Specimen Containers: Opening containers with internal pressure can release aerosols
  • Aerosol Control Measures:
    • Use Biological Safety Cabinets (BSCs): To contain aerosols
    • Use Sealed Centrifuge Rotors: To prevent aerosols from being released during centrifugation
    • Use Safety Pipettes: To prevent aerosols from being generated during pipetting
    • Disinfect Work Surfaces: Regularly disinfect work surfaces with appropriate disinfectant
  • Instruments should be routinely inspected for aerosol reduction, as well as follow the operation and maintenance manual

Decontamination

  • Definition: The process of removing or neutralizing contaminants on surfaces or in materials
  • Purpose:
    • Prevent Infections: To prevent the spread of infectious agents
    • Create a Safe Working Environment: To create a safe working environment for laboratory workers
  • Common Decontamination Methods:
    • Chemical Disinfection: Use of chemical disinfectants (e.g., bleach, alcohol) to kill or inactivate microorganisms
    • Autoclaving: Use of high-pressure steam to sterilize equipment and materials
    • Incineration: Burning contaminated materials to destroy infectious agents
  • Choice of Disinfectant:
    • Select a disinfectant that is effective against the specific agents being used
    • Follow the manufacturer’s instructions for use
  • Biohazardous waste must be discarded properly into biohazard disposal containers

Emergency Procedures

  • Spill Response:
    • Have a written spill response plan in place
    • Provide spill kits with all of the necessary materials
  • Exposure Response:
    • Have a written exposure response plan in place
    • Provide medical attention if a worker has been exposed
  • Training for all Laboratory Personnel:
    • Ensure that all laboratory personnel are trained in biosafety procedures
    • Provide regular refresher training

Key Terms

  • Biosafety: Practices designed to prevent exposure to potentially infectious materials
  • Biosafety Level (BSL): A categorization of biological agents based on risk
  • Personal Protective Equipment (PPE): Equipment worn to protect against biohazards
  • Aerosol: Airborne particles that can carry infectious agents
  • Decontamination: Removing or neutralizing contaminants