RNA interference studies are a powerful technology for high-throughput
screening. However, endpoint analyses only provide a snapshot of the
analyzed cellular phenotype, as it is not possible to measure
developmental changes over time. To address this, a research team led by
Stefan Wiemann and Ulrich Tschulena in the Division Molecular Genome
Analysis of the German Cancer Research Center (DKFZ) in Heidelberg,
Germany used the xCELLigence MP Instrument, from Roche (SIX:
RO, ROG; OTCQX: RHHBY), to quantify cell proliferation, without the
need for tagging or modifying sampled cells. As reported in the July
2011 (Zhang et al., Vol. 6, Issue 7) of PLoS ONE Online, they
showed that the measurement of impedance strength is positively
correlated with the number of cells attached to electrodes. Importantly,
impedance measurements reflect not only cell number and also the quality
of the cells’ interaction with their substrate, making this technology a
sensitive and reliable way to assess cell status, including cell
morphology, cell adhesion and cell viability.
The Heidelberg German Cancer Center research team integrated the Roche
xCELLigence MP Instrument into a high-throughput workflow for assaying
the effects of large numbers of different small interfering RNA (siRNA)
transfections. They used a human siRNA library to perform a whole kinome
screen, targeting 779 kinases and 80 cell cycle genes to analyze cell
proliferation in real time, by monitoring the dynamics of the cellular
responses after high-throughput gene knockdown. The team’s findings
showed that xCELLigence System measurements correlate with results
obtained using, in parallel, conventional endpoint analyses, in
particular Promega’s CellTiter-Blue and Roche’s WST-1 Cell Proliferation
Reagent for assaying cell viability, as well as qRT-PCR for quantifying
gene expression. However, the dynamic data obtained with the xCELLigence
System allowed to identify the timing after transfection where the
effect was maximal and to sort genes according to these time points.
"We have carried out a human kinome RNAi screen using xCELLigence with
electrical impedance as output. This screen has confirmed previously
identified inhibitor genes, as well as activators of cell proliferation.
Our data establish the technology of the xCELLigence system as a novel
tool amenable for high-throughput screening, opening new avenues in the
dynamic cellular analysis of phenotypes induced by RNAi and other
perturbations,” summarizes Stefan Wiemann, one of the authors of the
study and Head of the Division Molecular Genome Analysis at DKFZ.
The xCELLigence MP Instrument uses proprietary software and E-Plates 96
to measure electronic cell impedance using sensor electrodes.
Computer-controlled signal generation and automatic frequency scanning,
enable continual precise detection of changes in cell behavior using
96-well culture plates.
About Roche
Headquartered in Basel, Switzerland, Roche is a leader in
research-focused healthcare with combined strengths in pharmaceuticals
and diagnostics. Roche is the world’s largest biotech company with truly
differentiated medicines in oncology, virology, inflammation, metabolism
and CNS. Roche is also the world leader in in-vitro diagnostics,
tissue-based cancer diagnostics and a pioneer in diabetes management.
Roche’s personalised healthcare strategy aims at providing medicines and
diagnostic tools that enable tangible improvements in the health,
quality of life and survival of patients. In 2010, Roche had over 80,000
employees worldwide and invested over 9 billion Swiss francs in R&D. The
Group posted sales of 47.5 billion Swiss francs. Genentech, United
States, is a wholly owned member of the Roche Group. Roche has a
majority stake in Chugai Pharmaceutical, Japan. For more information: www.roche.com.
For life science research only. Not for use in diagnostic procedures.
XCELLIGENCE is a trademark of Roche.
E-PLATE and ACEA BIOSCIENCES
are registered trademarks of ACEA Biosciences, Inc. in the US.
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