Technical Articles

The CyQuantiFluor™ Cell Viability Assay Kit is a homogeneous detection kit based on DNA-specific fluorescent dyes. Its core principle is: DNA-binding dyes can penetrate the membranes of live cells and bind to nuclear DNA to produce strong fluorescence, with fluorescence intensity proportional to the number of viable cells; background-shielding dyes cannot enter live cells but can block fluorescence signals from DNA released by dead cells and extracellular DNA, ensuring detection specificity. This method does not rely on cellular metabolic state and directly quantifies the DNA content of live cells, offering advantages such as simple operation (one-step addition), high signal-to-noise ratio, and excellent stability. It is suitable for tumor cell proliferation assays and high-throughput compound screening.

In cell-based pharmacological screening, tumor proliferation research, and in vitro cytotoxicity evaluation, accurate live cell counting is the core prerequisite for reliable data. Traditional metabolism-dependent detection reagents such as MTT and CCK-8 are prone to interference from metabolic fluctuations and drug effects, leading to frequent numerical deviations. Conventional nucleic acid staining kits often suffer from interference by extracellular free DNA, with non-specific fluorescence elevating background values, hindering the implementation of high-throughput screening. U-爱Bio's self-developed CyQuantiFluor™ Cell Viability Assay Kit leverages dual-dye cooperative shielding technology, breaking free from metabolism-dependent limitations. With its homogeneous operation advantages, it has become the preferred tool for cell proliferation, cytotoxicity, and high-throughput small-molecule drug screening.

Cell viability and proliferation assays are among the most fundamental and essential experimental techniques in cell biology, drug screening, and toxicology research. Traditional methods such as MTT and CCK-8 rely on the activity of intracellular metabolic enzymes to convert substrates into colored or fluorescent products, thereby indirectly reflecting the number of viable cells.

In 1989, researchers collectively named the substance that promotes vascular endothelial cell permeability as vascular endothelial growth factor. The initial functions of VEGF primarily included promoting the proliferation of vascular endothelial cells, angiogenesis, and increasing vascular permeability.

Insulin-like growth factor-I is a peptide growth factor structurally homologous to insulin, playing a central regulatory role in physiological processes such as cell proliferation, differentiation, metabolism, and survival.

The Fibroblast Growth Factors (FGFs) family is a group of signaling molecules that play crucial roles in cell proliferation, differentiation, migration, and tissue development, extensively involved in various biological processes such as embryonic morphogenesis, tissue homeostasis maintenance, and post-injury repair.

Human epidermal growth factor receptor 2 (Her2) is a key member of the ErbB receptor tyrosine kinase family, playing a central role in regulating cell proliferation, differentiation, and survival signaling pathways.

Nucleolin (NCL) is a multifunctional nuclear protein distributed in the nucleolus, cytoplasm, and cell membrane, involved in regulating key biological processes such as rRNA synthesis, cell cycle progression, cell proliferation, and apoptosis.

PDGF-AA is a key member of the platelet-derived growth factor family, serving as a critical signaling protein that plays a central role in cell growth, migration, and survival.

The core mission of fluorescent cell viability assays is to rapidly, accurately, and quantitatively determine the proportion of live and dead cells within a population.