Magnetics Business & Technology - September/October 2021 - 9

FEATURE ARTICLE
beads provide a user an addressable substrate on which to
perform multiple bio-analytical reactions in a single well. In the
instrument, the beads pass through a red laser which excites the
internal dyes to distinguish the microsphere set. Then, a green
laser excites the fluorescent reporter dye to determine the result
of the assay.
There are several advantages to the magnetic particles over
traditional ones. With the use of a magnetic separator, they can
be separated from solution quickly and easily. This improves
percent recovery during handling and wash steps and facilitates
assay automation.
Luminex offers two magnetic separators, one is a plate separator
and the other a tube separator. The plate separator is a modified
plate magnet intended to separate a 96-well plate of MagPlex
microspheres during assay preparation steps. The side clasps
on this magnet have been specially designed to hold a roundbottom
plate securely to the magnet, enabling the user to quickly
decant it over a waste container.
The magnetic microspheres are typically produced in a concentration
of 2.5 million and 12.5 million beads/ml and are packaged
in 1 ml and 4 ml vials. The company makes two magnetic particle
coupling kits for biomolecule assay development and bio-separation,
one with bead sizes of 200nm and the other 1µm.
MagPlex-TAG Microspheres
Among the magnetic bead products are MagPlex-TAG microspheres
that allow users to easily design a nucleic acid liquid
bead array by hybridizing " TAGed " primers or probes to the surface
of the beads. The particles are dyed into spectrally distinct
sets, or regions, allowing them to be individually identified by an
xMAP instrument. Each of the uniquely color-coded beads has
a unique 24 base DNA sequence, called an " anti-TAG, " covalently
coupled to its surface. Users can quickly and easily design
custom bead arrays simply by adding a complementary " TAG "
sequence to their primers or probes of interest and hybridizing
those primers or probes to the anti-TAG sequences on the addressable
microsphere.
In July, Luminex was acquired for about $1.8 billion by Italian
diagnostics and life science company DiaSorin.
For more info, see www.luminexcorp.com and www.diasoringroup.com.
Avidin-coated
magnetic beads
Other magnetic beads from Luminex include its Avidin-coupled
magnetic microspheres to characterize peptides or proteins.
Avidin is a protein found in raw egg white. These beads are
avidin-coupled paramagnetic microparticles that have been color
coded into 100 spectrally distinct sets or regions. Each bead can
be used as the substrate on which an assay can be performed.
Because each of the beads is uniquely color coded, they can
be quickly distinguished by an xMAP instrument, which allows
interrogation of up to 100 different analytes simultaneously from
a single sample.
www.MagneticsMag.com
September/October 2021 * Magnetics Business & Technology 9

http://www.luminexcorp.com http://www.diasoringroup.com http://www.diasoringroup.com http://ww.itg-electronics.com http://www.MagneticsMag.com

Magnetics Business & Technology - September/October 2021

Table of Contents for the Digital Edition of Magnetics Business & Technology - September/October 2021