Cell-Based Assays

Services

iFyber has expertise in cell-based assays for evaluating the effects of new biomaterials, medical devices, and investigational compounds on mammalian biological systems. We implement high throughput, repeatable, relevant, and quantitative in vitro assays that provide clients with robust data from which to plan future product development and verification efforts.

Medical technologies employ a diverse range of functional materials, from synthetic polymers to recellularized ECM scaffolds. This diversity can lead to variable chemical and biological interactions occurring at the cell or tissue interface. Whether you are looking to transfer or optimize an existing assay for use with your technology or develop one from scratch, our cross-functional expertise in cell biology and interfacial chemistry ensures a swift path to completed assay development and reliable, actionable results.

iFyber's specializes in developing cell-based assays for safety and efficacy testing, offering a variety of standardized and custom functional bioassays to evaluate the effects of a technology on biological responses at the cellular and tissue levels.

Explore iFyber's Cellular Testing Offerings

MTT Assay

ISO 10993-5 Biological Evaluation of Medical Devices - Tests for In Vitro Cytotoxicity

What Is It?

The MTT assay provides a quantitative assessment of cell proliferation by measuring the activity of mitochondrial enzymes that reduce the tetrazolium salt, MTT, to formazan crystals that are solubilized with acidified isopropyl alcohol. The resulting purple solution is quantified spectrophotometrically at 570 nm. Standard intra-assay controls include vehicle-only (usually cell media) and a relevant mammalian cell toxin to demonstrate appropriate test system response.

Why Use It?

MTT is widely regarded as the go-to assay for in vitro cytotoxicity testing and is used regularly in industrial and academic R&D laboratories. The MTT assay has been demonstrated to be a relevant predictor of in vivo biocompatibility performance, highlighting its usefulness as a screening assay for new biomaterials or investigational compounds. Using ISO as a guideline, a material is considered cytotoxic if cell viability falls below 70% of untreated control cells.

Live/Dead Staining

What Is It?

The LIVE/DEAD assay is used to determine both cellular membrane integrity and cytosolic enzymatic function in response to a test article. Assay functionality is based on the ability of healthy cells to exclude ethidium homodimer-1, and at the same time cleave the membrane permeable, non-fluorescent calcein AM to calcein through functional cytosolic esterase activity, yielding green cytoplasmic fluorescence. Membrane-compromised cells are permeable to ethidium homodimer-1, which binds to nucleic acids resulting in nuclear-localized red fluorescence.

Why Use It?

Unlike most standard cytotoxicity assays, the LIVE/DEAD assay enables concurrent determination of two key aspects of cellular health: membrane permeability and enzymatic function. Healthy cells show green fluorescence, whereas dying or dead cells appear red. Quantification can be carried out by analyzing images that are captured using fluorescence microscopy methods or by using a fluorescence plate reader for high throughput purposes. As such, it provides more detail to the client and can help guide further focused testing.

Tunel Assay

What Is It?

Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) is used to identify DNA fragmentation, a terminal hallmark of both apoptotic and necrotic cells. Modified dUTPs are incorporated by the enzyme TdT at the 3’-OH ends of fragmented DNA. The modified dUTPs can be fluorescently labeled allowing quantification of apoptotic/necrotic cell number. This assay utilizes a double staining approach where total DNA appears blue and fragmented DNA appears red.

Why Use It?

BRDU Assay

What Is It?

The BrdU assay is based on the fluorometric detection of the thymidine analog BrdU (bromodeoxyuridine), upon its incorporation into genomic DNA during cell proliferation. BrdU may then be detected using anti-BrdU antibodies, allowing assessment of the population of cells that are synthesizing DNA. This indicates cell proliferation rate and a measurement of the number of cells in S phase of the cell cycle.

Why Use It?

If a test article demonstrates cytotoxicity as determined by MTT or NRU assays, the client may want to know more. One of the first aspects of cellular function to be investigated is DNA replication. The BrdU assay enables direct comparison between the proliferative status of cells treated with the test article and control cells. A reduction in BrdU uptake by treated cells indicates that DNA replication, and thus cell proliferation, is being negatively impacted.