Dynabeads are
superparamagnetic spherical
polymer
A polymer () is a chemical substance, substance or material that consists of very large molecules, or macromolecules, that are constituted by many repeat unit, repeating subunits derived from one or more species of monomers. Due to their br ...
particles with a uniform size and a consistent, defined surface for the
adsorption
Adsorption is the adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. This process creates a film of the ''adsorbate'' on the surface of the ''adsorbent''. This process differs from absorption, in which a ...
or coupling of various bioreactive molecules or cells.
Development and description
Dynabeads were developed after
John Ugelstad managed to create uniform
polystyrene
Polystyrene (PS) is a synthetic polymer made from monomers of the aromatic hydrocarbon styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It i ...
spherical beads (defined as
microbeads) of exactly the same size, at the
University of Trondheim,
Norway
Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of ...
in 1976, something otherwise only achieved by
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...
in the
weightless conditions of
SkyLab
Skylab was the United States' first space station, launched by NASA, occupied for about 24 weeks between May 1973 and February 1974. It was operated by three trios of astronaut crews: Skylab 2, Skylab 3, and Skylab 4. Skylab was constructe ...
. Dynabeads are typically 1 to 5 micrometers in diameter. This is in contrast to
Magnetic-activated cell sorting beads, which are approximately 50 nm.
The technology behind the beads, called Dynabeads, was licensed to
Dynal in 1980.
Following a series of mergers and acquisitions, Dynal and Dynabeads are currently owned and produced by Invitrogen,
part of
Thermo Fisher Scientific
Thermo Fisher Scientific Inc. is an American life science and clinical research company. It is a global supplier of analytical instruments, clinical development solutions, specialty diagnostics, laboratory, pharmaceutical and biotechnology s ...
.
Applications
This discovery of Dynabeads revolutionised the liquid-phase kinetic separation of many biological materials.
Since being licensed to Dynal in 1980, this magnetic separation technology has been since used for the isolation and manipulation of biological material, including cells,
nucleic acids
Nucleic acids are large biomolecules that are crucial in all cells and viruses. They are composed of nucleotides, which are the monomer components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main classes of nucleic a ...
,
proteins
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, re ...
and pathogenic microorganisms.
The uniformity in size, shape, and surface area allow for reproducibility and help to minimize chemical agglutination.
Dynabeads are frequently used for ''cell isolation''.
Cell-types often of interest to purify may be specific
leukocyte
White blood cells (scientific name leukocytes), also called immune cells or immunocytes, are cells of the immune system that are involved in protecting the body against both infectious disease and foreign entities. White blood cells are genera ...
s, such as
CD4+ T cells,
stem cell
In multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can change into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type of cell ...
s, or
circulating tumor cells (CTCs). Dynabeads may be covalently linked to an
antibody
An antibody (Ab) or immunoglobulin (Ig) is a large, Y-shaped protein belonging to the immunoglobulin superfamily which is used by the immune system to identify and neutralize antigens such as pathogenic bacteria, bacteria and viruses, includin ...
that recognizes a specific protein on the surface of the target cell-type. Alternatively, Dynabeads may attach to the cell indirectly, either via
streptavidin on the Dynabead linking to a biotinylated
primary antibody, or a
secondary antibody
Secondary may refer to: Science and nature
* Secondary emission, of particles
** Secondary electrons, electrons generated as ionization products
* The secondary winding, or the electrical or electronic circuit connected to the secondary winding i ...
on the Dynabead linking to the primary antibody. Streptavidin linkage to the primary antibody allows Dynabeads to capture cells with lower expression of the surface protein.
[Cancer Res. 2013 Apr 1;73(7):2310-21. doi: 10.1158/0008-5472.CAN-12-2956. Epub 2013 Feb 1.Cholesterol loading and ultrastable protein interactions determine the level of tumor marker required for optimal isolation of cancer cells.Jain J, Veggiani G, Howarth M.]
See also
*
Plastic magnet
*
Flow cytometry
*
Magnetic-activated cell sorting
References
Further reading
*{{cite book , author1=Ashok Kumar , author2=Igor Yu Galaev , author3=Bo Mattiasson , title=Cell separation: fundamentals, analytical and preparative methods , publisher=Springer , year=2007 , isbn=978-3-540-75262-2 , url=https://books.google.com/books?id=b2oeaFzo8aEC&q=Cell+separation:+fundamentals,+analytical+and+preparative+methods
External links
Bead separation Ebook
Surface science
NASA spin-off technologies
Norwegian inventions