Flow cytometric cell sorting is a widely used technique for the purification of specific cell types from heterogeneous samples by electrostatic droplet charging. Operator protection from aerosols, potentially carrying bio hazardous sample constituents (e.g. HIV), generated during cell sorting experiments, is generally provided by placing cell sorting equipment in Class II Biological Safety Cabinets (BSC). The efficacy of this protection was evaluated, by running highly concentrated suspensions of fluorescent microspheres on a Becton-Dickinson InFlux cell sorter system under normal and failure mode conditions, with- or without a running BSC. In failure mode, high amounts of aerosol are produced because of (partial) obstruction of the “nozzle”. We used the Coriolis®μ air sampler system and counted fluorescent microspheres present in collected samples using flow cytometric analysis (BD SORP-LSRII).
With an operational BSC, in all scenarios tested, dispersion of aerosolized fluorescent microspheres into the laboratory environment is undetectable, or decreased to (below) background levels (1). Significant quantities are however liberated into the laboratory environment in the absence of a functioning BSC (2), especially in failure mode (3). Such aerosolized particles can still be detected after cessation of the failure mode scenario (4), even in the general laboratory environment (after) (Figure 2).
Conditions sampled were (1) no fluorescent microbeads running; (2) fluorescent microbeads running and deflected into collection tubes (“sorted”) at 50,000/sec; (3) fluorescent microbeads running at 50,000/sec in failure mode, and (4) no fluorescent microbeads running, 30 sec after interruption of failure mode. Each of these conditions was tested with – or without a running BSC.