Cell separation is a technique that isolates specific populations of cells based on their unique characteristics. It is a fundamental technique in cell biology research, widely used in pharmacological research, cancer research, immunological studies, stem cell research, and cell therapy research, among other fields.

Common cell separation methods include density gradient centrifugation, magnetic-activated cell separation, and fluorescence-activated cell separation (FACS). These methods range from low to high specificity, among which FACS can separate most of the cell types precisely while it is more complex to operate. Magnetic-activated cell separation, on the other hand, has a lower barrier to operation and can also isolate high-purity target cell populations.

Magnetic-activated cell separation: This method involves binding magnetic microbeads to target cells through biotin antibody. When the heterogeneous mixture passes through a magnetic column placed in the magnetic field, the target cells bound to magnetic beads are retained within the column, while non-target cells that are not bound to the magnetic beads flow through with the buffer. Finally, the column filled with target cells is removed from the magnet, and a buffer is added to elute the target cells.

Fluorescence-activated cell separation (FACS): After cells are labeled with various fluorescent markers, individual cells passing through a laser beam excite the fluorophores, emitting different colors. The detection of specific fluorescent signals triggers the collection of targeted cells, separating them from non-targeted ones. The collected data can be analyzed using specialized software to understand the cell’s properties, quantity, and characteristics.

Both widely utilized cell separation methods, these two methods are applied in different fields. Magnetic-activated cell separation is simple, low-cost, and requires minimal training for researchers to independently conduct experiments. It typically achieves over 95% purity of the targeted cell population, but it can only sort one type of target cell at a time. FACS allows for the setting of multiple fluorescent signals and channels, sorting multiple target cells in a single experiment, commonly with instruments that offer up to four channels.

However, flow cytometers are expensive, have a steep learning curve, and the process is complex and time-consuming; extended sorting times can significantly affect cell viability. Therefore, some researchers combine these two methods, using Magnetic-activated cell separation for a preliminary enrichment of target cells, followed by FACS, to improve the efficiency.