Measuring Containment of Viable Infectious Cell Sorting in High-Velocity Cell Sorters

Abstract

Background: With the advent of high-speed sorters, aerosols are a considerable safety concern when sorting viable infectious materials. We describe a four-part safety procedure for validating the containment. Methods: This procedure includes aerosol containment, physical barriers, environmental controls, and personal protection. The Aerosol Management System (AMS) produces a negative pressure within the sort chamber, where aerosols are forced through a HEPA filter. Physical barriers include the manufacturer's standard plastic shield and panels. The flow cytometer was contained within a BSL-3 laboratory for maximum environmental control, and the operator was protected by a respiratory system. Containment was measured by using highly fluorescent Glo-Germ particles under the same conditions as the cell sort. Results: Escaping aerosols were vacuumed for 10 min onto a glass slide and examined. With the AMS active and the cytometer producing the maximum aerosols possible, Glo-Germ particles remained within the sort chamber. Measurements taken directly outside the door averaged fewer than one particle per slide, and those taken at 2 ft away and on top of the sorter were completely negative. Conclusions: With this monitoring system in place, aerosols can be efficiently measured, thus reducing the risk to the operator while sorting viable infectious cells.