Using a Loop:

• Use a cooled loop for insertion into a culture
• Ensure the loop is completely closed
• Use short loops: the shank should be no more than 6 cm long to avoid vibrations
• Use a micro‐incinerator or pre‐sterilized plastic loops rather than flaming a loop in an open flame

Plating:

• Streak plates where the surface of the medium is smooth (i.e. avoid bubbles)

Pipetting:

• Use “to deliver” pipettes to avoid blowing out the last drop
• Drain pipettes gently with the tip against the inner wall of the receiving vessel
• Use pipettes with plugs to reduce contamination of the pipetting device
• Work over an absorbent, plastic‐backed pad to avoid aerosol dispersion from drops falling on hard surfaces
• Do not mix materials by alternate suction and expulsion through a pipette (use vortex mixer)

Centrifuging:

• Use sealed safety cups and sealed rotors
• Open cups inside a biosafety cabinet
• Allow cups to sit prior to opening to allow aerosols to settle if no biosafety cabinet available

Blending and Homogenizing:

• Use a laboratory blender with a tight‐fitting gasketed lid and leak‐proof bearings (domestic kitchen blenders leak and release aerosols)
• Wait as long a s possible before opening the lid after mixing

Using needles and syringes:

• When withdrawing a needle from a stoppered bottle, wrap the needle and bottle cap in a disinfectant‐soaked absorbent
• Use syringes with a Luer lock connector
• Dispose of needles directly into sharps container without further manipulation (needle‐cutting devices release aerosols)

Opening tubes:

• Avoid using tubes with push‐in closures (when opened, the film of liquid trapped between tube and closure breaks and releases aerosols)
• Use a vortex mixer instead of inverting tubes
• Wait 30 seconds after shaking a tube before opening

Pouring infectious liquids:

• Avoid pouring off supernatant – use pipettes instead
• Pour infectious liquid waste through a funnel where the end is below the surface of the disinfectant in the discard container; pour disinfectant through the funnel after use

Opening ampoules of lyophilized cultures:

• Avoid hasty opening by snapping the neck, which can lead to sudden inrush of air and dispersal of contents – instead make a file mark near the middle of the cotton plug and apply a red‐hot glass rod to crack the glass, allow time for air to seep into the ampoule and gently remove the top and plug
• Add liquid for re‐suspension slowly to avoid frothing

Breakage:

• Use plastic labware rather than glass (less likely to break which generates aerosols)

Source: Adapted from the Canadian Food Inspection Agency