Biomedical Engineering Reference
In-Depth Information
a
1 mm
Pump
Valve
Mixer
200 µm
d
Streptavidin-
(b-PNIPAAm)
b
36°C
Mixer
e
Heat,
capture
Cool and
Conjugate
Surface
grafted
PNIPAAm
36°C
and wash
release
Pump
f
T<LCST
T>LCST
T<LCST
36°C
c
g
Hot buffer
36°C
Enrichment
Cool and
and wash
release
h
Room
temp
T>LCST
T>LCST
T<LCST
i
= Hydrophilic
= Hydrophobic
Cold buffer
Room
temp
FIGURE 4.13
Capture,.release,.and.enriching.of.“smart”.conjugates.in.a.microluidic.reactor..The.
mixer. and. the. pump. were. operated. at. 5. Hz.. The. LCST. for. PNIPAAm. is. 36°C.. (From. John. M..
Hoffman,.Mitsuhiro.Ebara,.James.J..Lai,.Allan.S..Hoffman,.Albert.Folch,.and.Patrick.S..Stayton,.
“A.helical.low,.circular.microreactor.for.separating.and.enriching.''smart'.'polymer-antibody.cap-
ture.reagents,”.
Lab Chip
.10,.3130,.2010..Reproduced.with.permission.from.The.Royal.Society.of.
Chemistry..Figure.contributed.by.John.Hoffman.)
LCST, the luorescence intensity of labeled streptavidin-polymer conjugates was measured and
compared with the original bolus intensity. Under the correct conditions, 60% of a conjugate
bolus was captured and subsequently released. Enrichment of protein-polymer conjugates was
achieved by continuous conjugate low into the recirculator heated above the LCST, followed by
mixing, cooling and release of conjugates. Conjugate concentration was increased nine times
within 30 seconds of continuous low.
4.6 Chips for Genomics and Proteomics
Animals have thousands or even hundreds of thousands of genes. In 1990, the U.S. Department
of Energy and the U.S. National Institutes of Health formally founded a $3 billion project to
