xCELLigence Support

RTCA Technology

As cells adhere to the biocompatible gold microelectrodes that line the well bottoms in an E-Plate they impede the flow of electric current between electrodes. Using our proprietary algorithm, this impedance signal is converted to a specific parameter called Cell Index. The Cell Index is an excellent measure of what the cells are actually doing over time: proliferating, spreading, changing shape, dying, responding to specific stimuli, etc. The Cell Index measurement has been reviewed and accepted in over 700 peer-reviewed publications.

No. The electric field is extremely weak and non-invasive. Repeated studies at ACEA Biosciences and elsewhere have confirmed the technique to be harmless to the cells.

For all seven xCELLigence models the Stations that are placed inside the incubator are specifically designed to withstand the high temperature and humidity of laboratory incubators.

If the Control Unit is out of the WiFi range of the iCELLigence Station the data will not be lost and the experiment will not be interrupted. Once an experiment is started, the Station records and saves all the data. The saved data automatically synchronizes to the Control Unit once the WiFi connection is re-established. Data collected prior to a power outage will not be lost as long as the outage is less than 15 minutes in length.

RTCA E-Plate

Yes, each well is measured individually, in sequential fashion. Since the RTCA Instrument measures essentially the entire bottom surface of the well, the dynamic range of the system approaches 2 logs of cell growth – from 100 cells per well to confluence (depending on cell type). Also, well-to-well precision and accuracy are excellent. In our laboratory we typically achieve well-to-well CVs of less than 10%.

A: Yes. Cells can be nicely imaged directly on the E-Plate L8, E-Plate View 16, and E-Plate View 96 devices through the electrode-free viewing area.

Yes. E-Plates can be coated with any number of matrices to enhance or prevent cell attachment. Examples of amenable surface coatings include poly-L-lysine, fibronectin, and collagen IV.

E-Plates are made of biocompatible materials and are tissue-culture treated at the time of manufacture. They are sterile, and designed for single use. Cell growth on E-Plates is essentially identical to what is observed on most standard cell culture plates.

Like conventional cell culture plates, the E-Plate is not designed or intended for reuse.

Cells attach to the planar gold electrode sensor array at the bottom of the wells. These electrodes cover approximately 70-80% of the well bottom surface area. All components of the E-Plates are biocompatible, sterile, and tissue-culture treated.

RTCA Applications and Data

The time-dependent curves generated by the RTCA Instrument yield a wealth of information about the actual kinetics of cellular events occurring in the wells. Cell morphology changes yield curves which differ distinctly from those resulting from changes in cell number. The use of appropriate control treatments and/or orthogonal assays during initial xCELLigence assay development make it easy to differentiate between cell morphology change and cell proliferation in an RTCA curve. Typically, however, simply viewing the cells in a microscope is sufficient for making this distinction.

The RTCA systems are used for a broad range of research applications, including cell proliferation, cytotoxicity, cell adhesion, RTK, GPCR, RNAi functional analyses, natural killer cell activity, ADCC, CDC, virus neutralizing antibody detection, and bacterial toxin neutralizing antibody detection. This list is not exhaustive. For a more comprehensive list of applications, please click the “Applications” tab within each of the seven xCELLigence product pages.

Hundreds of cell lines as well as some primary cells have been tested. Most adherent cell types can be analyzed on the RTCA System. Cells which are not naturally adherent have also been successfully studied by tethering them to the well bottom using antibodies.  In the absence of this special treatment, non-adherent cells generally cannot be detected by the sensors and thus cannot be measured very well directly. However, in certain experiments this can be a benefit. This is especially true for cell-mediated cytotoxicity, where the killing of adherent target cells by suspension effector cells (Natural Killer, Cytotoxic T-lymphocytes, etc.) is being measured. For an exhaustive list of cells that have been successfully analyzed using xCELLigence, please download our list of verified cell lines.

RTCA has been used so extensively over the past 10 years that a massive body of data (over 700 publications) and experience now enable the correlation of RTCA curve features with distinct biological processes (such as cytoskeletal rearrangement upon GPCR stimulation or the induction of apoptosis by a DNA damaging agent). Importantly, if different drugs or treatments induce the same biological phenomena they give rise to similar RTCA curves. For this reason, a novel drug’s mechanism of action (MOA) can often be inferred simply by comparing the RTCA curve it induces with a panel of RTCA curves from drugs whose MOA is known. Most importantly, appropriate controls and/or orthogonal assays can be used to link the features of an RTCA curve with specific cellular/biochemical processes.

Application Notes

Videos: Research Presentations

Optimization of Chimeric Antigen Receptor (CAR) T Cell Design Guided by Sensitive Assessment of B Cell KillingAdoptive cellular therapy using chimeric antigen receptor (CAR) T cells has produced significant responses in patients with CD19+ hematological malignancies. Most clinical trials...Read More
Bispecific Antibody Constructs Mediate Immunotherapeutic Retargeting of Effector Cells Towards HBV Infected Target Cells

Dr. Felix Bohne
Institute of Virology, German Research Center for Environmental Health, Helmholtz Zentrum München

Chronic viral hepatitis is a major public health threat. Current strategies for eradicating the virus and treating virus-induced liver disease and hepatocellular carcinoma are very limited. Novel therapeutic strategies are in urgent need. Immunotherapeutic retargeting of effector cells is a promising approach to… Read More
Unraveling Kinase Inhibitor Cardiotoxicity with Cardiomyocyte Impedance Assays

Dr. Sarah K. Lamore
AstraZeneca Pharmaceuticals, Waltham, MA

Cardiovascular (CV) toxicity is a leading cause of drug failure. Though implementing earlier testing has successfully reduced hERG-related arrhythmias, additional assays capable of identifying other functional CV effects remain elusive. There is a pressing need to…Read More
Targeting the Reattachment of Circulating Breast Tumor Stem Cells to Reduce Metastasis

Dr. Stuart Martin
University of Maryland School of Medicine, Baltimore, MD

Breast tumor stem cells that are circulating in the bloodstream can invade distant tissues and lie dormant for long periods of time. Reemergence of these disseminated stem cells as metastatic tumors is a primary cause of patient death. In this webinar… Read More
Advances in Toxicity Bioassays – Unleashing the Power of Real-Time Cell Analysis for Health Risk Assessment

Dr. Stephan Gabos
University of Alberta, Edmonton, AB (Canada)

Modern public health protection requires ongoing surveillance of environmental media (water, air, food and soil) for potentially harmful chemicals. There is currently an unmet need for in vitro toxicity assays with higher sensitivity, lower interference, and better… Read More
A Novel in vitro Approach to Study Biocompatibility and Wound Healing

Dr. Sandra N. Garcia
Kinetic Concepts Inc., San Antonio, TX

Negative Pressure Wound Therapy (NPWT), where a vacuum is applied to an acute or chronic wound, has proven extremely effective for promoting would healing. The success of NPWT lies in its ability to draw the edges of a wound together, to promote granulation,…Read More


Using Impedance-Based Approaches for Measuring Antigen-Specific Cytotoxic T cell Activity

Dr. Keith L. Knutson
Mayo Clinic, Jacksonville, FL
The Vaccine & Gene Therapy Institute of Florida, Port Saint Lucie, FL

Immunotherapy, where the immune system is harnessed to treat and/or prevent disease, holds great promise in the fight against cancer. One noteworthy facet of cancer immunotherapy is the development of cancer-specific vaccines. In this webinar Dr. Keith L…Read More
Identifying Novel Combination Therapeutic Targets for Pancreatic Cancer

Dr. Melissa L. Fishel
Indiana University School of Medicine, Indianapolis, IN

Pancreatic cancer is presently a largely incurable disease. Increasing evidence suggests that effective treatment strategies will need to simultaneously target multiple molecular mediators of critical functions in pancreatic ductal adenocarcinoma cells (PDAC)…Read More
Cardiac Toxicity Assessment Using Stem Cell-Derived Cardiomyocytes

Dr. Matthew F. Peters
AstraZeneca Pharmaceuticals, Boston, MA

Cardiac toxicity is a major hurdle in drug development. In this webinar Dr. Matthew F. Peters of AstraZeneca Pharmaceuticals (Boston, MA) discusses the utility of combining ACEA Bioscience’s xCELLigence® Cardio system with stem cell-derived cardiomyocytes...Read More