Biomedical Engineering Reference
In-Depth Information
0
a
c
-50
Cell
Glass
-100
-150
Single channel
recordings from
alamethicin in a
lipid bilayer
-200
b
Aperture (top view)
-250
-300
0
2
4
6
8
10
12
14
16
2 µm
t [ms]
FIGURE 5.53
A.glass.patch.clamp.chip.capable.of.detecting.single-ion.channel.activity..(From.Niels.
Fertig,.Robert.H..Blick,.and.Jan.C..Behrends,.“Whole.cell.patch.clamp.recording.performed.on.a.
planar.glass.chip,”.
Biophys. J.
.82,.3056-3062,.2002..Adapted.with.permission.of.Elsevier.)
channels (in CHO cells as well as in lipid bilayers, see
Figure 5.53
). Unfortunately,
although glass patch-on-a-chip devices are most promising because of their chemi-
cal surface similarity with micropipettes, the particle accelerator required for ion
track etching is not available in most research institutions. However, this technol-
ogy is now commercially available through Nanion Technology, which has reported
a high-throughput system capable of obtaining whole-cell I-V curves (voltage-gated
as well as ligand-gated channels in HEK-293 cells) from 96 cells simultaneously (the
“SynchroPatch 96”).
In 2005, bioengineer Luke Lee from the University of California at Berkeley and his
colleagues proposed a radical new approach to patch-clamping: instead of letting the
cells settle onto a planar aperture (which is the most obvious mimic of a pipette aper-
ture), they reasoned that the cells should also be able to produce good seals against
a cornered or “lateral” aperture (i.e., the end of a small microchannel, as depicted in
Figure 5.54
). For the patch array in cell-attached mode, the seal resistance was 150
3 µm
Data
acquisition
(a)
(b)
(c)
Microscope
objective
20 µm
FIGURE 5.54
PDMS.patch.clamp.chip.with.a.lateral.aperture..(From.Cristian.Ionescu-Zanetti,.Robin.
M..Shaw,.Jeonggi.Seo,.Yuh-Nung.Jan,.Lily.Y..Jan,.and.Luke.P..Lee,.“Mammalian.electrophysiol-
ogy.on.a.microluidic.platform,”.
Proc. Natl. Acad. Sci. U. S. A.
.102,.9112-9117,.2005..Copyright.
(2005).National.Academy.of.Sciences,.U..S..A.)
