Biomedical Engineering Reference
In-Depth Information
of.separation.protocols,.particularly.electrophoresis.(Wu.et.al..2008;.Kenyon.et.al..2011)..
Nanoscale.materials.are.increasingly.incorporated.into.these.devices.to.improve.the.sep-
aration.processes.
15.3.2.1 Nanoparticles for Bioseparations
The. majority. of. nanoparticles. used. for. bioseparations. are. magnetic. nanoparticles. due.
to. the. ease. of. separation. by. the. application. of. a. magnetic. ield. (Franzreb. et. al.. 2006)..
As. discussed. in. Section. 15.3.1.2. with. respect. to. enzyme. immobilization,. in. general,. the.
particles.employed.are.superparamagnetic;.hence,.they.do.not.agglomerate.in.the.absence.
of.a.magnetic.ield,.but.can.be.easily.collected.with.a.strong.permanent.magnet..Afinity.
separations,.which.are.based.on.speciic.biological.or.chemical.interactions,.are.the.most.
commonly.reported,.although.ion-exchange.particles.have.also.been.reported.(Table.15.3)..
However,.a.wide.range.of.chemistries.have.been.investigated.for.functionalization.of.the.
magnetic. nanoparticles.. The. most. common. afinity. puriication. at. both. the. macroscale.
and. nanoscale. is. binding. of. a. His-tagged. protein. (typically. six. histidine. residues. at.
either. the. amino. or. carboxy. terminus. of. the. protein). by. an. immobilized. metal. ligand.
(most.commonly.Ni
2+
)..Building.on.their.previous.work.creating.magnetic.nanoparticles.
for. drug. delivery. and. medical. imaging,. Sahu. et. al.. (2011). prepared. superparamagnetic.
(6-8.nm). nanoparticles. (Fe
3
O
4
). by. standard. chemical. precipitation. methods,. followed. by.
TABLe 15.3
Functionalized.Magnetic.Adsorbents.Suitable.for.Binding.Proteins
Ligand
Target Molecule
Supplier
M
2+
-charged.
imino.
diacetic.acid
His-tagged.fusion.proteins,.proteins.with.
surface-exposed.His,.Cys,.and.Trp.side.chains
Chemagen
a
;.Micromod
b
;.Dynale
c
Glutathione
Glutathione-S-transferase.(GST).fusion.proteins
Promega
d
;.Micromod
b
Streptavidin
Biotinylated.proteins
Bangs
e
;.Chemagen
a
;.Micromod
b
;.
Seradyn
f
;.Dynal
g
;.Promega
d
Biotin
Fusion.proteins.with.streptavidin.group.or.analog
Bangs
e
Protein.A.or.G
Monoclonal.antibodies
Bangs
e
;.Micromod
b
;.Dynal
g
−COOH
Molecules.with.positive.(cationic).net.charge
Bangs
e
;.Chemagen
a
;.Micromod
b
;.
Seradyn
e
;.Dynal
g
−SO
3
Molecules.with.positive.(cationic).net.charge
Chemicell
h
−NH
2
Molecules.with.negative.(anionic).net
Bangs
e
;.Chemagen
a
;.Micromod
b
;.Dynal
g
−DEAE
Molecules.with.negative.(anionic).net
Chemicell
h
−N(CH
2
CH
3
)
2
Molecules.with.negative.(anionic).net
Chemicell
h
Source:
. With.kind.permission.from.Springer.Science+Business.Media:.
Appl. Microbiol. Biotechnol
.,.Protein.puri-
ication. using. magnetic. adsorbent. particles,. 70,. 2006,. 505-516,. Franzreb,. M.,. Siemann-Herzberg,. M.,.
Hobley,.T.J.,.and.Thomas,.O.R.T.,.Table.1.
a.
Chemagen.Biopolymer.Technology,.Baesweiler,.Germany;.http://www.chemagen.de
b.
Micromod.Partikeltechnologie.GmbH,.Rostock,.Germany;.http://www.micromod.de
c.
Dynale.offers.magnetic.adsorbent.particles.with.TALON.functionalization.for.the.puriication.of.HIS-tagged.
proteins.
d.
Promega,.Madison,.Wisconsin.
e.
Bangs.Laboratories,.Fishers,.Indiana;.http://www.bangslabs.com
f.
Seradyn,.Indianapolis,.Indiana;.http://www.seradyn.com
g.
Dynal.Biotech,.Lake.Success,.New.York;.http://www.dynalbiotech.com
h.
Chemicell.GmbH,.Berlin,.Germany;.http://www.chemicell.com
