Cell contamination concerns have led many researchers to switch from open systems with manual workflows to closed platforms, which offer all-in-one automation. Switching systems helps maintain sterility, even on an open bench, says Alejandro Montoya, M.S., a senior product manager of advanced cell culture at Corning Life Sciences.
"Open systems require more manipulation to add density gradient media and other manual steps inherent in open centrifugation, which can make them more prone to microbial contamination," Montoya said. "In a closed system, you can greatly reduce the number of processing steps, which, in turn, minimizes contamination risk."
Closed systems may protect against outside contaminants, and certain platforms can remove undesired components from samples more effectively than manual processes can. For example, Corning's X-SERIES Cell Separation Platform includes X-LAB® and X-WASH®, which support sensor-guided cell isolation and cell washing, respectively.
In the X-LAB System, samples get transferred into a single-use, sterile cartridge, either through tube welding or aseptically via Luer lock connectors or syringes. From there, samples flow into a preprogrammed centrifuge, where the accelerometer and sensors in the Control Module track G-force and cell layering. Once the cells are stratified, the cartridge's valves automatically open and close to move samples into their respective compartments.
"Using a combination of an accelerometer, intelligent sensors and a multichamber device cartridge, the X-LAB System is very effective at separating out populations such as red blood cells, which are a common source of inherent cellular contaminant when you're isolating immune cell populations," said Josey, who spoke about the technology for a BioProcess International webinar. "It can reduce red blood cell levels down to below 1 percent without the need for the lysis step, compared to the 3 percent achieved with lysis."
The ability to eliminate introduction of density gradient media and skip lysis can help prevent contamination, as these reagents are fraught with inherent risks through required manipulation and extended exposure.
"The amount of time that you expose your cells to the lysis buffer can have a contamination impact and affect cell viability," Josey said. "Alternatively, not needing to add an additional reagent is one less processing step that you have to do, and every step comes with added risk. So if you're looking at sources of external contamination, not having to do lysis is certainly beneficial."