Cell health assays

Cell viability assays measure the relative number of live cells in cell populations, in response to a drug or other perturbation, by involving different experimental techniques depending on the required sensitivity, the throughput, and the model system. Viability assays can be multiplexed with toxicity and cell death assays to provide additional information regarding the relative number of dead cells and type of cell death. We offer assays suited for a broad range of applications that are based on bioluminescent, fluorometric, or colorimetric readouts. Endpoint assays provide sensitive, high-throughput formats, whereas real-time, live-cell assays repeatedly monitor over time and generate multiple data points from a single assay.

The essential cell viability assays are summarised in the table below: 

In addition to the above most commonly used assays we also offer alternative approaches to suit specific experimental needs, contact us for more info.

Example output:

One of the main events that occur after cell death is the loss of membrane integrity, which allows chemicals or proteins to freely enter or exit the cell. Taking advantage of this phenomenon, we are able to evaluate the cytotoxicity of a given compound either by determining the exact number of dead cells stained with cell-impermeant fluorescent dyes or indirectly, by measuring the activity of enzymes that leak into the extracellular medium after cell membrane damage.

Membrane integrity dyes are cell-impermeant and only able to enter cells with a compromised plasma membrane. We use the nucleic acid-binding dyes (eg. DRAQ7, PI, 7-AAD, EthD-1, SYTOX) which are nonfluorescent in aqueous media but exhibit increased fluorescence upon binding to double-stranded DNA (dsDNA) or RNA. They allow for the fast and accurate evaluation of cytotoxicity and for multiplex experiments with other fluorescent dyes.

Enzyme leakage-based cytotoxicity assays detect extracellular glucose-6-phosphate dehydrogenase (G6PD), lactate dehydrogenase (LDH) or adenylate kinase (AK) released from damaged cells. Released enzymes activity can be quantified by a coupled enzymatic reaction in which provided substrates (lactate and NAD+, NADP+ or ADP) are converted to NADH, NADPH or ATP which further can be measured using different assay chemistries. The generated color, fluorescent or luminescent signal is proportional to the amount of ezyme present in analysed sample. There is no need for cell lysis so repeated samples of supernatant can be taken from wells over time without disrupting the cells themselves. This allows for kinetic analysis of cell death and multiplexing with other tests.

The essential cell toxicity assays are summarised in the table below:

In addition to the above most commonly used assays we also offer alternative approaches to suit specific experimental needs, see more info.

Example output:

Cell-death assays are crucial tools for drug discovery and development, providing insights into the mechanisms of programmed cell death and drug-induced cell death. By using these assays, researchers can assess the efficacy and safety of potential drug candidates, optimize drug dosages, and identify potential adverse effects.

There are several types of cell death, including apoptosis, necrosis, and autophagy. Discriminating between these different types of cell death is crucial for understanding their mechanisms and identifying potential therapeutic targets. Apoptosis is a programmed cell death pathway that is tightly regulated and involves caspase activation, while necrosis is an uncontrolled cell death pathway that is stimulated by external factors. Autophagy is a process of cellular recycling that can lead to cell death when its levels are excessive.

Understanding the type of cell death induced by a drug candidate is important for drug candidate profiling because different types of cell death have different mechanisms and implications for drug efficacy and safety.

The commonly used cell death assays are summarised in the table below:

In addition to the above assays we also offer alternative approaches to suit specific experimental needs, see more info.

Example output: