Cell sorting facs machine

The FACS (Fluorescence-Activated Cell Sorting) machine is an essential instrument for isolating specific cell populations based on their optical properties.

About this subject

FACS (Fluorescence-Activated Cell Sorting) is a flow cytometry technique that allows live cells to be separated with high speed and purity. Using lasers and detectors, the instrument identifies cells labeled with fluorochromes and directs them individually into different tubes or plates via an electrostatic deflection system. Developed in the 1960s, this technology revolutionized immunology, oncology, and cell biology.

In practice, a cell suspension is injected into a thin stream that passes through a laser beam. Each cell is analyzed for parameters such as size (forward scatter), granularity (side scatter), and fluorescence. When a target cell is detected, an electric field charges the droplet containing the cell, which is then deflected into a specific container. The process can sort thousands of cells per second, with viability exceeding 90% for mammalian cells.

FACS is crucial in cell therapy research, such as producing CAR-T cells for cancer treatment, and isolating stem cells, rare lymphocytes, or genetically modified bacteria. It also enables simultaneous multiparametric analysis of up to 40 markers using advanced spectral detectors. Clinical applications include leukemia diagnosis and HIV monitoring, where CD4+ lymphocyte counting is routinely performed by flow cytometry.

Frequently Asked Questions

What is the difference between FACS and flow cytometry?

Flow cytometry is the technology that analyzes cells in suspension using lasers, while FACS is a specific application that physically separates (sorts) cells based on measured parameters. All FACS instruments are flow cytometers, but not all cytometers perform sorting.

Do cells sorted by FACS remain viable?

Yes, when optimized, FACS maintains high cell viability (above 80-90%) because the process is sterile and fast. However, mechanical stress and pressure can reduce viability in some cell types, requiring protocol adjustments.

What are typical applications of FACS in laboratories?

FACS is used to isolate rare cell subtypes (e.g., circulating tumor cells), purify genetically modified cells, obtain homogeneous populations for sequencing, and in immunotherapy protocols such as generating CAR-T cells.