The objective of magnetic bead cell isolation is to enrich a specific cell type from a mixed population. The technique is also be used to isolate proteins, DNA, and RNA for further research or therapeutic purposes. The versatility and specificity of magnetic bead cell isolation is made possible by functionalized bead surfaces that specifically recognize a target molecule. Magnetic beads are composed of a ferrous iron-oxide core surrounded by a polymer shell, or a magnetic ‘pigment’ embedded in a polymer matrix.
What is Fluorescence Activated Cell sorting?
Fluorescence activated cell sorting (FACS) is a technique to identify, count, and sort cells marked with a fluorescent label by suspending them in a fluid stream and passing them through a laser. The basic principles, first patented in 1953, were modified over the subsequent decade, and the first commercialized instrument was produced in 1968. Since then many advancements and variations on the theme have shaped modern instruments.
During the last weeks we have reviewed several aspects of biomagnetic cell sorting, a process which facilitates the quick and targeted removal of specific cells from a heterogeneous solution. Cell sorting is essential for a number of purposes, from technological to investigative and biomedical. By harnessing the properties of magnetic beads, biomagnetic separation (BMS) allows cells to be isolated for additional downstream applications, without adversely affecting their form or function.
Use of magnetic beads provides an efficient and innovative method of harnessing magnetic separation processes to non-magnetic, cellular targets of biological origin. When beads are attached, the ensemble of the cells and beads becomes a magnetizable object.
Coated magnetic beads are capable of interacting with and binding to a corresponding target within a sample. Binding specific biomarkers to the surface functional group present on the bead (e.g., streptavidin) ensures that the interaction is limited to specific cells. Recovery of material for further studies is greatly simplified when beads are concentrated from suspension, by means of an external magnet.
Magnetic activated cell sorting has demonstrated extreme utility for isolating virtually all cell types from complex biomedical samples and cultured cells. Antigens (cell-surface proteins) provide the extracellular characteristics for enriching heterogeneous cell-mixtures typical of magnetic cell sorting. Attachment of target-specific antibodies to beads' surfaces generates sorting, securing intact cells to allow isolation within a complex liquid suspension.
Cell sorting is widely used in research and clinical therapy. The latest advances in stem cell therapy, tissue engineering and regenerative medicine show the potential of cells derived from different tissues. Sorting cells from a heterogeneous population enables the study of the different isolated types, but also allows for the introduction of enriched cell populations to a patient. The use of highly selective separation procedures is also critical to improve cell-based treatments on stem cell therapy, tissue engineering and regenerative medicine.
Magnetic nanoparticles form the basis for capturing and separating molecules from a sample solution. The particles act as carriers, sequestering target molecules via attachment sites present on their surface, and shuttling them in the direction of an induced magnetic force. The attachment sites are customizable, endowing the particles with specificity and allowing them to be effective for a wide range of applications ranging from investigative to technological and biomedical.
Cell separation improves understanding of cell function, generating discoveries for improved medical practice and research. Yet, experimental procedures for removing cells from their natural environment can adversely affect their function and expressed physical traits - morphology, or biochemical/physiological properties. Thus, separation processes appropriate to the biomedical or related task at hand are required to assure optimum process efficacy. Magnetic bead cell separation efficiently utilizes the principle of the attractive power of magnetic force on selected particles in liquid solution.