Cell sorting facs machine

The Fluorescence-Activated Cell Sorting (FACS) machine is a vital tool in modern biology, enabling the separation of live cells based on their fluorescent properties.

About this subject

The Fluorescence-Activated Cell Sorting (FACS) machine combines flow cytometry with physical cell separation. Its principle involves labeling cells with fluorophore-conjugated antibodies or expressing fluorescent proteins like GFP. Cells are aligned in a thin fluid stream and pass one by one through a laser beam. Detectors measure fluorescence and light scatter, and a computer decides whether to collect or discard each cell. An electrostatic deflection mechanism diverts target cells into collection tubes, yielding pure, viable populations.

Developed in the 1960s by Leonard Herzenberg and colleagues at Stanford University, FACS revolutionized immunology and cell biology. It is now essential for isolating lymphocyte subsets, stem cells, circulating tumor cells, and even bacteria. Purity of sorted populations can reach 99%, and speeds exceed 70,000 cells per second in advanced instruments.

Clinical applications include adoptive cell therapy, such as isolating T cells for cancer treatment (CAR-T). In basic research, FACS enables study of cellular heterogeneity in tumors, immune responses, and embryonic development. Maintaining sterile conditions and sorting live cells for subsequent culture are key features.

Interestingly, "FACS" is a trademark of Becton Dickinson but is used generically for fluorescence-based cell sorters. Related techniques like MACS (magnetic-activated cell sorting) complement its applications.

Frequently Asked Questions

How does a FACS machine work?

FACS uses flow cytometry to analyze fluorophore-labeled cells. A laser excites the fluorophores, detectors measure fluorescence, and a computer decides whether to collect the cell. An electrostatic mechanism deflects it into the appropriate tube.

What is the difference between FACS and MACS?

FACS sorts cells by fluorescence using laser and electrical deflection, achieving high purity and multiparameter analysis. MACS uses magnetic beads conjugated to antibodies and a magnetic field, which is faster and cheaper but with lower resolution.

What are the medical applications of FACS?

FACS isolates specific cells for therapies, such as T cells for cancer immunotherapy, and diagnoses hematological diseases like leukemia by counting abnormal cell subpopulations.