Applications of Cytotoxicity Screenings
Cytotoxicity assays are mainly utilized in cytotoxicity screenings of large compound libraries, to identify potentially toxic compounds during the initial stages of drug development. Another use for these assays is in cancer therapeutics, as a means to discover specific compounds which target cells that are dividing rapidly. Finally, the findings of a certain cytotoxicity assay can be used as a guideline for the concentrations of further cytotoxicity tests.
IonTox offers a plethora of different in vitro cytotoxicity assays to assist companies in performing a reliable and cost-effective screening to discover the cytotoxic potential of their compounds. These assays include standard cell viability screens (ATP), predictive models with multiple endpoints, as well as more specific tests to assess liver toxicity, mitochondrial toxicity, and oxidative stress. It is also not uncommon for IonTox to utilize more than one assay when performing a thorough cytotoxicity screening.
IonTox provides a range of cytotoxicity assays. Along with providing a detailed final report for each study, we will suggest follow-up studies to further your organization’s research goals.
IonTox’s cytotoxicity panel provides information on subcellular mechanisms and potential adverse effects. Several parameters are examined, including membrane integrity (GST), mitochondrial function (MTT and ATP), and cell number (propidium iodide). Also, the toxic half-maximal (TC50) is compared to the efficacy half-maximal (EC50) to potentially develop an in vitro therapeutic index.
For the phospholipidosis/steatosis assay, IonTox utilizes a combination of LipidTox Red and HepG2 cells. Testing is done in a 96-well plate, and results are determined using fluorescent probes with 540 nm excitation and 680 nm emission. The assay consists of a complete determination of both phospholipidosis and steatosis, along with a positive and negative control sample for seven different testing concentrations at a single time point
This assay measures three different endpoints -Nrf2 signaling pathways, reduction in GSH, and activation of DCFDA- to determine the amount of oxidative stress through metabolism. The assay includes a positive and negative control sample and can be performed on H4IIe rat cells, HepG2 human cells, or primary hepatocytes. Every compound is tested in triplicate for seven distinct concentrations during a single time point.
IonTox’s Cell Viability assay (ATP), called FastTox, compares novel compounds to reference drugs to determine general toxicity during the early stages of drug development. HepG2 or H4IIE cells are exposed to six concentrations of the same test compound, and their ATP levels are calculated after an incubation period. The sponsor is responsible for supplying the test compounds as a 10mM stock solution in DMSO. Results for up to 100 compounds should arrive within a week.
The Glu/Gal assay aims to determine mitochondrial damage by comparing the amount of ATP that HepG2 cells produce via oxidative phosphorylation rather than via glycolysis in a media that consists of galactose at 10mM instead of glucose at 25mM. The assay includes eight different concentrations, two-time points at 24 and 72 hours, and Tamoxifen and Rotenone as media controls.
Our Expertise at IonTox
IonTox is a biotechnology company specialized in the field of in vitro research. By developing and furthering the realm of in vitro technology, we aim to improve the methods for predicting human adverse effects from chemical exposure in the earliest stages of the drug discovery process.
Whether your company is seeking to achieve a successful regulatory submission or to further pharmacokinetic knowledge around a specific compound, we can provide guidance on the best path forward.
Contact us to consult on which assays or panels are most applicable for your project.