Cell sorting facs machine

The FACS (Fluorescence-Activated Cell Sorting) machine is a high-precision instrument that sorts individual live cells based on their fluorescent and light-scattering properties.

About this subject

FACS technology, derived from flow cytometry, enables real-time analysis and sorting of cells. The principle relies on lasers exciting fluorophores bound to specific antibodies or fluorescent proteins expressed by cells. Cells in suspension pass through a narrow laminar flow and are excited one by one. Sensors detect fluorescence and light scatter, generating a multiparametric profile that defines characteristics such as size, granularity, and expression of surface or intracellular markers.

Sorting is achieved via electrostatic deflection. Droplets containing individual cells are electrically charged based on system decisions and then deflected by electric fields into distinct collection tubes. This process can reach speeds of thousands of cells per second with purity exceeding 99% under optimized conditions. Applications include isolating rare cell subpopulations (e.g., hematopoietic stem cells or circulating tumor cells) and preparing samples for single-cell RNA sequencing.

The development of FACS revolutionized immunology and cell biology. In the 1960s, the first flow cytometers were created by Wolfgang Göhde and Leonard Herzenberg, the latter credited with inventing FACS. Modern instruments like the BD FACSAria or Sony SH800 offer up to 4 lasers and 18 detectors, enabling simultaneous analysis of multiple parameters. Maintenance requires rigorous calibration with reference beads and periodic cleaning to prevent contamination and ensure accuracy.

Despite its utility, FACS has limitations: it requires cells in suspension and can cause mechanical stress. Alternatives like magnetic sorting (MACS) are less precise but gentler. The choice depends on the application, purity versus cell viability. Life science laboratories and research hospitals often maintain a core cytometry facility with specialized technicians to operate these complex instruments.

Frequently Asked Questions

What does FACS stand for?

FACS stands for Fluorescence-Activated Cell Sorting, a technique derived from flow cytometry that allows sorting of individual live cells based on their fluorescent properties.

What is the difference between FACS and MACS?

FACS uses lasers and optical detection to sort cells with high purity (up to >99%) and multiparameter analysis, whereas MACS (magnetic-activated cell sorting) uses antibody-conjugated magnetic beads and a magnetic field, which is faster and less stressful but yields lower purity and no multiparameter capability.

What is FACS used for in biomedical research?

FACS is used to isolate rare cell subpopulations such as stem cells, circulating tumor cells, or specific lymphocytes; purify cells for culture or transplantation; and prepare samples for single-cell RNA sequencing, enabling studies of cellular heterogeneity and development of therapies.