Cytotoxicity and Cell Viability

Are you working with precious cells, antibodies, patient samples, or compound? Do you have the time required to repeat an assay over multiple time points? Endpoint assays only provide a snapshot of what your cells are doing. To see the full cytotoxic response you need time, money and effort to repeat your experiment over multiple plates and cells. The Maestro impedance assay captures everything on one plate; revealing not only the degree but also the kinetics of cell death. See the Technology tab for more information on how impedance works.

The cytotoxicity of a treatment depends on the delivered dose. With increasing concentration of Dox, the real-time resistance (left) and cytolysis (middle) curves show increased cytotoxicity. The cytolysis was evaluated as a function of the concentration (right) and fit according to the Hill equation. The analysis estimates the 50% effective concentration (EC50) of Dox to be 0.43 micromolar at 72 hours post-dose.

(Left) SKOV3 cancer cells were cultured at 5k cells per well in a CytoView Z 96-well plate. After 24 hours of culture, the SKOV3 cells were dosed with Dox at 9 concentrations in half-log increments from 0.01 to 100 micromolar. The highest concentrations of Dox produced the lowest measured resistance over time. (Middle) The Dox treated wells were compared with the “No Treatment Control” condition to compute cytolysis. The cytolysis was higher for increasing concentrations of Dox. (Right) The Hill equation was fit to the cytolysis data at 72 hours post-dose. The EC50 in this assay was 0.43 micromolar according to the dose response analysis.

The number of cells directly scales with impedance. The correlation is so robust it can meet ISO 20391-2 standards for reproducibility. When compared to a traditional viability endpoint, like an MTT assay, the results directly correlate. In vitro cell viability assays on the Maestro Z, however, are not limited to a single time point.

(Left) Calu-3 cells plated from 6400-51200 cells/well as measured by the Maestro Z. (Middle) 4 hours after plating impedance measurements show a linear relationship that directly correlates with (Right) optical MTT assay results.

(A) 24 hours after plating, Dox is applied and recorded for an additional 36 hours. (B) Dox effect at 30 hours post-dose. (C) Using on-plate controls for cell growth (No Treatment) and death (Tergazyme), the percent cytolysis was tracked in real time throughout the experiment and kill time₅₀ was calculated.

The figures above highlight the dynamic cytotoxic response over time. The percentage of cytolysis, or cell death, can be tracked in real time, and the time to 50% cell death (kill time₅₀) provides insight into the kinetics and efficacy of a treatment's cytotoxicity. 

All products and application data are for research use only and not intended for human diagnostic or therapeutic uses.

Applications of cytotoxicity and cell viability assays:

• >> CAR-T or other immune cell-mediated killing of cancer cells

• >> Viral infection and antiviral effectiveness

• >> Environmental toxicant

• >> Safety and toxicity testing

Why measure in vitro cytotoxicity and cell viability with Maestro Z?

• >> Analyze the kinetics and capture cytotoxic responses that take minutes to weeks.

• >> Research the biology, not the chemistry. No dyes or reagents to interfere.

• >> More data, less work. One plate for the whole experiment.

• >> Up to 96 wells, save time, cells, media and compound

• >> No complicated assay protocols, just simple cell culture techniques.

• >> Sensitive and reliable. Maestro Z can meet the high reproducibility standards of ISO 20391-2