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

Exploring the Role of iPSC-Cardiomyocytes in Drug Discovery and Safety AssessmentHuman induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are increasingly utilized in basic biology research, drug discovery applications, and for studies of disease mechanisms. The opportunity to measure the contractility, viability, and electrophysiology of hiPSC-CMs in real time over extended periods can provide researchers unique mechanistic insights into the roles cardiomyocytes play in both normal development and cardiac disease. In this ... Read More

Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are increasingly utilized in basic biology research, drug discovery applications, and for studies of disease mechanisms. The opportunity to measure the contractility, viability, and electrophysiology of hiPSC-CMs in real time over extended periods can provide researchers unique mechanistic insights into the roles cardiomyocytes play in both normal development and cardiac disease.

In this special webinar, scientists using hiPSC-CMs will describe new approaches aimed at enhancing assessment of hiPSC-CM functionality. The speakers will also discuss how these approaches can be used to explore compounds that modulate the force of cardiomyocyte contraction or to assess the safety and efficacy of drugs and drug combinations targeting cardiac tissue.

In this webinar, you will gain insights on:

  • New instrumentation to assess cardiomyocyte contractility, viability, and electrophysiology
  • Label-free, real-time techniques to assess the “beating” of cardiomyocytes as a biologically-relevant measure of cardiomyocyte function
  • Use of electrical pacing for further maturation of cardiomyocytes
  • Techniques to detect functional cardiotoxicity

In addition, you will also be able to ask your own specific questions of the speakers during a live question-and-answer session following the presentations.

Learn More about the xCELLigence CardioECR       Click here
Featured Speaker:

Armando Lagrutta, PhD
Merck & Co. Inc.
Kristina Green, PhD
MyoKardia, Inc.

Moderator:

Patrick C.H. Lo, PhD
Senior Editor,
BioTechniques

 

 

WEBINAR – Optimization of Chimeric Antigen Receptor (CAR) T Cell Design Guided by Sensitive Assessment of B Cell KillingFeatured Speaker: Dan MacLeod Ph.D. Precision BioSciences, Inc. Dr. MacLeod received his Ph.D. in Molecular Pathology and Biomedical Sciences from the University of California, San Diego (UCSD). He subsequently conducted postdoctoral research at the International AIDS Vaccine Initiative Neutralizing Antibody Center at the Scripps Research Institute. Dr. MacLeod is currently leading a group in Precision BioScience’s Cell Therapy Research team, ... Read More

Featured Speaker:

Dan MacLeod Ph.D.
Precision BioSciences, Inc.

Dr. MacLeod received his Ph.D. in Molecular Pathology and Biomedical Sciences from the University of California, San Diego (UCSD). He subsequently conducted postdoctoral research at the International AIDS Vaccine Initiative Neutralizing Antibody Center at the Scripps Research Institute. Dr. MacLeod is currently leading a group in Precision BioScience’s Cell Therapy Research team, focused on expanding the use of Precision’s propriety ARCUS gene-editing technology to engineer T cells for cancer therapy.

Abstract: 

Adoptive cellular therapy using chimeric antigen receptor (CAR) T cells has produced significant responses in patients with CD19+ hematological malignancies. Most clinical trials to date have used autologous patient cells, which incur significant manufacturing challenges and costs and are not feasible for many patients with advanced disease state.

At Precision BioSciences, we have developed an allogeneic method using our proprietary ARCUS™ gene-editing technology to generate “universal” CAR T cells from healthy donors. These cells are engineered to eliminate expression of the endogenous T cell receptor making them safe for transfer to unrelated patients. By integrating the CAR transgene at a single genomic site, we can tightly control the level of CAR expression on the cell surface. We further optimize the cells by designing new CAR T constructs that include modifications to the extracellular binding domains as well as the intracellular signaling domains.

Evaluating the impact of these new modifications requires sensitive methods to assay CAR T cell function. Traditional methods for evaluating cytotoxicity cannot effectively predict in vivo activity of a CAR T product; this is because they assess short-term killing potential rather than the ability to expand, persist, and exhibit serial killing. We have used the ACEA xCELLigence instrument for both B Cell Killing Assays and Leukemic Cell Killing Assays to test multiple CAR constructs with modified ectodomains, endodomains, and other modifications, and we have found this platform sensitive enough to detect subtle yet significant differences in performance not observed in traditional killing assays. Furthermore, the sensitivity of the instrument has enabled us to evaluate CAR constructs using cell numbers that are orders of magnitude lower than other assays, greatly enhancing our throughput and capabilities.

For full video, watch above or click here.

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