Benchtop Cell Sorter Validated in Biosafety Containment Setting

Fluorescent-activated cell sorting (FACS) is often the most appropriate technique to obtain pure populations of a cell type of interest for downstream analysis. The ability to sort pure populations of immune cells is a critical tool for immunologists.

Aerosol droplets can be generated during the sort, which poses a biosafety risk when working with samples containing risk group 3 pathogens such as Francisella tularensis, Mycobacterium tuberculosis, Yersinia pestis, and severe acute respiratory syndrome coronavirus 2.

Pulmonary pathogen specialists at the Rocky Mountain Laboratories (Hamilton, MT, USA) performed aerosol testing as part of the biosafety evaluation of the MACSQuant Tyto (Miltenyi Biotec, Bergisch Gladbach, Germany) a completely closed, cartridge-based cell sorter. They also established quality control procedures to routinely evaluate instrument performance. Aerosol testing was performed on FACSAria II (BD Biosciences, San Diego, CA, USA) with the Aerosol Management System disabled as a positive control for aerosol generation.

The scientists reported that before usage of the Tyto on the benchtop to sort cells at BSL-3, it was necessary to empirically determine if aerosols were generated during the cell sort procedure. They utilized a novel method using internally fluorescent 1.0 μm beads to perform aerosol testing on the Tyto. These beads were uniform in size and intensely fluorescent in the fluorescein isothiocyanate (FITC) channel.

As a positive control, they detected aerosols generated by the in-house FACSAria II when the Aerosol Management System was disabled, and the flow stream disrupted. As expected, beads were detected on the coverslip after only a 30-second exposure. The MACSQuant Tyto did not produce aerosols as part of the sort procedure. The scientists established a purity of >96%, depletion yield of >80%, and sort efficiency of >85% as benchmarks that must be met during quality control testing.

The authors concluded that they utilized the Tyto cell sorter in their BSL-3 laboratory. This instrument not only has a small footprint but most importantly does not generate aerosols during the sort procedure. The use of this technology will improve current immunological studies in containment laboratories by allowing a greater number of scientific groups to isolate cell types involved in the immune response to high-consequence pathogens for downstream applications. The study was published on November 24, 2021 in the journal Applied Biosafety.

Related Links:
Rocky Mountain Laboratories
Miltenyi Biotec
BD Biosciences