Cell Sorting
Main Techniques for Cell Sorting
Flow Cytometry / Fluorescence-Activated Cell Sorting (FACS)
Cells are suspended in a fluid and passed single-file through a laser.
Detectors measure light scatter (size/complexity) and fluorescence (markers).
The machine charges droplets containing individual cells, which are then deflected into collection tubes.
Applications: isolating stem cells, immune cell subsets, cancer cells.
Magnetic-Activated Cell Sorting (MACS)
Uses magnetic beads conjugated with antibodies that bind to specific cell markers.
Magnetically labeled cells are separated in a magnetic field.
Advantages: fast, gentle, scalable.
Limitations: less precise than FACS.
Density Gradient Centrifugation
Cells are separated based on density using gradients (e.g., Ficoll, Percoll).
Common for separating blood mononuclear cells from whole blood.
Simple but not highly specific.
Microfluidics & Lab-on-a-Chip Sorting
Uses miniaturized channels, fluid flow, and sometimes acoustics or dielectrophoresis.
Gentle and can handle small samples.
Growing field for point-of-care diagnostics.
Applications of Cell Sorting
Research: studying cell populations, gene expression, and signaling.
Clinical: isolating stem cells for regenerative medicine, enriching immune cells for therapies (e.g., CAR-T).
Diagnostics: detecting circulating tumor cells, immune profiling in infections.
Biotechnology: selecting high-yield cell lines for drug or protein production.