Sera-Mag Carboxylate-Modified Magnetic Beads & SpeedBeads have free carboxyl groups on the surface for convenient covalent coupling of target molecules (proteins, peptides, and amine-modified ligands) via primary amines (NH2).
Wide application range: Carboxylic groups on the surface form covalent amide bonds with proteins, peptides or amine-modified ligands for use in many downstream applications including protein purification, DNA sample preparation and clean-up, protenomicsand immunoassays.
Convenient one-step or two-step coupling: Carbodiimide chemistry allows rapid formation of stable bonds to minimize ligand leaching.
Fast magnetic separation: Available in original Sera-Mag format or Sera-Mag SpeedBeads version for faster magnetic response and shorter assay times in clinical diagnostic tests.
High performance: Excellent sensitivity and low nonspecific binding for greater accuracy; different levels of hydrophobicity/hydrophilicity available.
The entire range of Sera-Mag encapsulated magnetic particles are characterized by high binding capacity, excellent stability, low nonspecific binding, high sensitivity, very slow settling rates, and fast reaction kinetics.
The core of each particle is made by a free radical emulsion polymerization of styrene and acid monomer. One (Sera-Mag) or two (Sera-Mag SpeedBeads) layers of magnetite are then coated onto this core, while the surface is modified to minimize non-specific binding of proteins. Due to the extra magnetite layer, SpeedBeads respond twice as fast to a magnetic field as the original Sera-Mag particles.
Magnetic particles may need further processing before they are ready to use for your particular application. Therefore, we can provide personalized magnetic bead solutions that fit seamlessly into your workflows, often saving you time and money in the process. We aim to provide product that is ready to use with little or no need for further modification. This allows you to focus on the science that matters. To learn more, please visit our custom manufacturing services page.
The convenient “one-step” protocol for covalent coupling of proteins to Sera-Mag or SpeedBeads carboxylate-modified particles involves the following steps (see protocol guide for full details):
Prepare a reagent mixture containing MES buffer, protein solution, and magnetic particles, and mix for 15 minutes at room temperature on a mixing wheel or other device.
Add freshly prepared EDAC solution at the pre-determined optimal concentration, and mix for one hour at room temperature on a mixing wheel or other device.
Pellet particles by centrifugation (10 to 30 minutes in a standard microcentrifuge) and decant the supernatant.
Perform two washes with MES buffer or a high pH buffer of your choice, pelleting particles by centrifugation and using ultrasonication to resuspend pellets between washes.
Resuspend final pellet to desired % solids with a buffer such as MES that does not contain blocking proteins.
Perform a BCA protein assay to determine the amount of protein-bound on the particles.
For pre-activation with carboxyl-reactive crosslinking reagents, a simple two-step procedure is also available.