LabAutomation 2006 - SLAS

TP11
Carsten Haber
Ion Gate Biosciences
Cohasset, Massachusetts
carsten.haber@iongate.de
Where Laboratory Technologies Emerge and Merge
Co-Author
Wolfgang Doerner
IonGate Biosciences GmbH
A Novel Label-free Electrogenic Assay Principle for Transporter Proteins
IonGate Biosciences (Frankfurt/Germany – www.iongate.de) has developed an electrochemical biosensor which permits robust and labelfree
screening of electrogenic membrane proteins on solid supported membranes (SSMs).
The technology can be scaled up in highly parallel fashion for high-throughput screening applications. The central element of the instrument
is a specially treated gold surface which is designed to specifically adsorb transporter-containing membrane targets. The membrane
components self-assemble on the gold surface to form a large number of small vesicles doped with transporter molecules. These solid
supported membranes are highly stable and enclose isolated small volumes of buffer from the bulk solution. The SSM acts as a carrier for
the membrane fragments, and in parallel as a high-capacitance, low-conductance electrode. Via rapid solution exchange, substrate ions
are moved by energy (ATP)-driven transport processes out or into the vesicle cell and trigger a capacitive charging current on the sensor
surface.
The sensitivity of the sensor is sufficient to detect electrogenic binding of substrates or single turnover reactions within the protein. To date,
seventeen different transporter proteins have been investigated using IonGate’s biosensor.
TP12
Elaine Heron
Labcyte Inc.
Sunnyvale, California
Elaine.Heron@labcyte.com
Co-Author(s)
Richard Ellson
Shehrzad Qureshi
Richard Stearns
Labcyte Inc.
Non-Invasive Hydration and Volume Measurements of Solutions in Storage Tubes
Re-sealable tubes are prevalent as containers for compound library storage because they can be individually accessed and replaced.
However, when aliquots are repeatedly removed from tubes, there is an ever increasing uncertainty about both the volume of the solution
and the amount of water that was been absorbed. Hydration is especially difficult to measure with existing methods such as Karl Fischer
titration, a destructive method that requires opening the tube. Other methods have been described, but these approaches are not able to
measure the entire possible range of water content. We describe the use of acoustics to simultaneously measure both the volume and the
water content in water/DMSO solutions containing library compounds. These parameters are determined by measuring both the time it
takes for the sound to travel to the liquid/air interface and amplitude of sound energy reflected. This method does not require opening the
tubes or removing samples, and the measurement is not hindered by the presence of some formats of 2-D bar codes on bottom surface.
Analysis time as well as accuracy and precision of volume and % water measurements will be presented for 2-D bar coded tubes as well
as for tubes held in frames.
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