Cardiomyocytes in Voltage Clamp and Current Clamp byAutomated Patch Clamp
Andrea Brüggemann, Claudia Haarmann, Markus Rapedius, Tom Goetze, Ilka Rinke, Michael George, Niels Fertig.
Nanion Technologies, Munich, Germany.

Abstract
In recent years, human stem cell-derived cardiomyocytes have proven to recapitulate key featuresof human cardiac electrophysiology in vitro. Furthermore, it has become apparent that the intact
ensemble of cardiac ion channels is necessary to determine proarrhythmic effects reliably. Hence,due to their increasing availability, stem cell-derived cardiomyocytes have become the preferredchoice of cardiac cells.

Pharmacology on human iPSCderived Cardiomyocytes (currentclamp)

Pharmacology on human stem cellderived Cardiomyocytes (voltageclamp)

200 pAThis poster summarizes the promises and challenges of combining iPSC-derived cardiac myocyteswith automated patch clamp. Features like high throughput, temperature control, easy internal
solution exchange and full automation make planar patch clamp a desired method forcharacterizing iPSC-derived cardiomyocytes.

200 msSodium and Potassium
Raw currents and IVs
constructedfromminimum(NaV)
andmaximum (KV) current
from human iPSC-derived
cardiomyocytes.

With this poster, we show our progress on these challenges. Two automated patch clamp platforms,
the Patchliner, as a medium throughput, and the SyncroPatch 384PE, as a high throughput device,
were used for this study.

DC
Spontaneous action potentials.
control
100nM Isoproterenol
washout

Pharmacological measurements in voltage clamp as well as current clamp will be shown also underphysiological temperatures and perforated patch.
SodiumRawcurrent
trace
examples and average
dose response curve for
lidocaine as obtained
from human iPSC-derivedcardiomyocytes.

HTS Patch clamp performance of human
iPSC-derived cardiomyocytes (compared toa stably transfected cell line)

iCell2Cor.4U

20 ms

Action potentials repeatedly
induced by 1 ms current
injections.

20mV

β-adrenergic agonist Isoproterenol
enhances action potentials.

Calcium
Raw current traces as
response to an IV protocol
and average IV curves
under control conditions
and in the presence of
10 mM nifedipine.

SyncroPatch 384/768PE

SyncroPatch 384/768PE

Left: Exemplary raw current traces under control conditions (dark blue) and in thepresence of 100 mM erythromycin (light blue) at room temperature (top) and at 35 oC(bottom). Obvious are the changed kinetics due to temperature. Right: Apparent theshift in the average dose response curves at RT and 35 oC. Similar results obtained on
the SyncroPatch 384PE are shown on this poster as well (top right hand corner).

SummaryCalciumRawcurrent
trace
examples and average
dose response curve fornifedipine as obtained
from human iPSC-derived
cardiomyocytes.

CHO Nav1.7

PatchlinerPatchliner

Patchliner

One of the biggest challenges of planar patch clamp in this context is the fact that individual cells
cannot be chosen, but cells will be selected randomly. In addition cells have to be harvested before
the application to the patch clamp chip and cannot be patched as adherent cells.

hERG Pharmacology at 35 oC

L-Type Ca2+ channel blocker
Nifedipine
shortens
actionpotentials.

L-Type Ca2+ channel activator Bay K
8644 prolongs action potentials.

Nanion’s Patchliner and SyncroPatch 384/768PE are both planar patch-clamp
platforms with medium and high throughput, respectively. Both achieve highand robust success rates. This their additional features of1) enabling temperature controlled experiments,
2)

being suitable systems
cardiomyocytes, andfor3)

having a current clamp amplifierexperiments

withstemcell-derived

They combine the necessary features for successful drug discovery!

High Throughput Automated Patch Clamping: Voltage and Current Clamp
Nifedipine

Expanded view of a train ofaction potentials elicited inpresence of 5 mM Barium. ForCa channel inhibition, 5 µM
Nifedipine was applied.

Online Analysis of the same cellfrom top graph. APD90 wascalculated before and afteraddition of 5 µM Nifedipine.
Screenshot of the data acquisition and analysis software used on the SyncroPatch 384PE. CDI’s
Cardiomyocytes2, Axiogenesis’ Cor.4U and Anaxon’s NaV1.7 (CHO) were run on 1/3 of a plate each,
as indicated. In voltage clamp mode Na currents were evoked with a step protocol.
Obvious from the screenshot are the high success rates which are achieved with the scd CMs.
Comparison of APD90and APD50

Sager, P.T., et al., 2014.

Methods

Cardiac AP and currents

Ion channel currents that mediate
cardiac myocyte action potential

The experiments presented on this poster were performed on the Patchliner or SyncroPatch 384/768PE(AP; left). Voltage clamp protocol
The SyncroPatch 384PE is a patch clamp module that can be used with a state-of-the-art pipetting robot, e.g. Biomek FX

as indicated. Experiments were all performed in regular electrophysiological salt solutions. Both systems

and examples of the 6 different(Beckman Coulter). Figure illustrates six different cardiac channels recorded simultaneously on the SyncroPatch 384PE.

currents

have the option of temperature control and the their amplifiers the option of current clamp (Patchliner:Screenshot shows data acquisition and analysis software performing recordings from HEK or CHO cells expressing theSyncroPatch 384PE.

HEKA EPC10, SP 384PE: Tecella).

CiPA stipulated ion channels activated within one single experiment on the SyncroPatch 384PE.

recordedontheRaw voltage action potentials (leftfigure, black and light blue traces)from Cor.4U cells. APs were recorded
in 5 mM Barium. Different shapes andAP duration can be observed. 5 µM
Nifedipine was applied for Calcium
channel inhibition. An immediateshortening of the APD can beobserved (blue trace).

Planar Patch Clamp:“Cell towards the aperture”