Expand each of the subsections below for further information

Room SAFB-532 in the Flow Cytometry Facility is classified as Containment Level (CL) 1. CL1 samples (low-risk cell lines and organisms, and fixed CL2 samples) can be analysed or sorted on all instruments located in room 532 on level 5 of the Sir Alexander Fleming Building – BD Fortessa I and III, Penteon, FACSAria III and Cytek Aurora.

It is the user’s responsibility to make sure their samples fall into this category. Even “CL1” samples are still biological material with a residual risk, and also several of the chemicals used for sample preparation are carcinogens or otherwise unhealthy (e.g. like formaldehyde, all nuclear stains, sodium azide etc.). Therefore, all users must:

  • Log their projects in the Facility Biosafety Database,
  • Complete a risk assessment form,
  • Read the required Standard Operation Procedures and Code of Practice,
  • No unfixed infected samples may be analysed,
  • All samples brought into the facility should be contained within lidded tubes and a secondary container i.e. a polystyrene box.

Containment Level (CL) 2 samples (live human samples, Hazard Groups 2 and 3 derogated pathogens and GMO Class 2 organisms) can be analysed in the Fortessa II located in room 628 on level 6 of the Sir Alexander Fleming Building, in the FACS Calibur located in lab 3.22 on level 3 of the Flowers Building, and in the CellStream located in lab 5.22 on level 5 of the Flowers Building. Airborne pathogens can only be analysed in the CellStream. These samples can also be sorted in the FACSMelody located in room 522 on level 5 of the Sir Alexander Fleming Building or in the FACSAria located in lab 3.22 on level 3 of the Flowers Building. Both sorters and the CellStream are encased in class II biosafety cabinets to avoid the release of aerosols during sorting and analysis procedures.

All users must:

  • Make sure their samples fall into the CL2 category,
  • Make sure that their Project Registration Form includes CL2 work,
  • Upload Bio1 forms and SOPs to RADAR for approval by the Biosafety Team before work commences,
  • Create an entry in the Facility Biosafety Database. Upload an approved Bio1 form that includes the nature of the work, location of the instrument, spillage procedure and, in the case of the Aria III, the use of sorting,
  • Develop a Standard Operations Procedure,
  • Complete a risk assessment form before work commences,
  • Undergo an additional induction for CL2 work in the facility.


  • Should be contained within lidded tubes and a secondary container i.e. a polystyrene box.
  • Tubes should be visually inspected for cracks before placing on CL2 cytometers. If the tube is cracked, aerosols will be released when the system becomes pressurised.
  • Transport, spillage protocol, disinfection and waste disposal for CL2 samples should be described in the Facility Biosafety Form.
  • FIXED human samples, Hazard Group 2 pathogens and GMO Class 2 organisms can be analysed in CL1 cytometers. 
  • No unfixed infected samples above CL2 may be analysed or sorted in the facility.
  • Users that wish to run samples containing any agents above CL2 must FIX samples to inactivate the agent.
  • Fixed samples can be sorted after the fixative is removed.

For more information on biological safety and containment levels, see the Approved List of Biological Agents (including classification) on the Health and Safety Executive website. Some information is also on Imperial College's Biological Safety website.