Alley-Oop Learning Center Group

Main Techniques for Cell Sorting

1. 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.

2. 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.

3. 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.

4. 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.