Surface-Activated Dynabeads

Dynabeads magnetic beads are available for covalent coupling of ligands to the bead surface. One can choose beads of different sizes, with a hydrophobic or hydrophilic surface, and with a variety of surface chemistries. For optimal results, select the right bead based on ligand type (Table 1). Note that in most applications several Dynabeads products can be used. Depending on the magnetic bead type, the ligand can be directly linked to the bead surface or indirectly linked through a reactive intermediate. Protocols can take place in a single tube, with just a few handling steps.

The Dynabeads are pipetted into a vial and the ligand is added. Incubate the vial for covalent coupling of the ligand to the Dynabeads, add target containing sample, incubate again for affinity-binding of target. Use a magnetic stand or rack for magnetic separation, and remove supernatant. Wash and either boil in SDS for page or elute for pure target protein.

Table 1. Choose the right surface-activated Dynabeads for your ligand and target sample

Ligand	Target	Dynabeads Tosyl- activated	Dynabeads Carboxylic Acid	Dynabeads Amine	Dynabeads Epoxy
Antibody	Low MW antigen1 or peptide
	Protein or antibody
	Protein complex
	Organelles				2
	Phage1
	Virus
	Bacteria
	Cells3
Antibody Fragment	Phage1 or antibody
Protein	Phage or carbohydrate
	Nucleic acid
Peptide	Phage1 or antibody
Carbohydrate	Antibody
Low MV antigen	Antibody
Nucleic acids, oligonucleotide, aptamer, PNA	Nucleic acid binding proteins1			4
	DNA1, RNA1 or PCR amplicons1			4
Enzyme	Substrate or target for enzyme degradation
Organic chemistry derivatization, including introduction of new functional groups

 Best product choice for listed ligand and target.
Alternative choice for listed ligand and target.
 Can be used for listed ligand and target.
¹ Dynabeads pre-coupled with streptavidin may be the best product choice.
² Dynabeads M-450 Epoxy.
³ Dynabeads M-450 Epoxy are recommended for isolation, stimulation, and expansion of cells.
⁴ Bifunctional crosslinkers may be introduced to immobilize oligonucleotides onto the surface of Dynabeads Amine.