Cell growth assays

The number of cells present depends on the level of cell growth and cell death. Therefore, detection of cell death is a commonly used approach to average cell growth. Apoptosis induction can be studied most easily by detection of subdiploid cells or analysis of DNA degradation profiles on the flow cytometer after DNA extraction and propidium iodide staining. 

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Data Mappers and Slurpers to efficiently batch upload high-throughput enzyme inhibition and high content cell growth assays... 

Cory, A. et al. 1991. Use of an aqueous soluble tetrazolium/formazan assay for cell growth assays in culture. Cancer Commun 3, 207-212. 

Squatrito, R., Connor, J., and Buller, R. 1995. Comparison of a novel redox dye cell growth assay to the ATP bioluminescence assay. Gynecol. Oncol. 58, 101-105. 

Hayashi, S. Kohayashi, T Honda, H. Simple and rapid cell growth assay using tetrazolium violet coloring method for screening of organic solvent tolerant bacteria. J. Biosci. Bioeng. 2003, 96, 360-363. 

ICso is defined as the concentration of drug required to inhibit cell growth by 50% compared to a control. The IC50 values were calculated from the graphs obtained from the in vitro cytotoxicity assays and are the average of three independent experiments, each performed in triplicate. 

TABLE 5.1 IC50 (nM) Values from Cell-Growth Inhibition Assays... 

Denizot F, Lang R 1986 Rapid colorimetric assay for cell growth and survival. Modifications to the tetrazolium dye procedure giving improved sensitivity and reliability. J Immunol... 

A very versatile piece of equipment that is affordable for individual laboratories is the microplate reader. This allows multiple samples to be analyzed at once, commonly in a 96-well format, although 384- and 1536-well formats are available. Typical measurements that can be performed include UV-Vis absorbance, fluorescence, or luminescence, allowing a range of assays to be performed, such as cell growth, enzyme kinetics, enzyme stability, or enzyme-linked immunosorbent assay [60-62]. Functionality can be increased by the use of liquid dispensing systems or automatic plate handling. 

Figure 9.3 Activation of T-cells by interaction with macrophage-displayed antigen. Activation results in IL-2 production, which acts in an autocrine manner to stimulate further T-cell growth and division. IL-2 thus represents the major regulatory molecule responsible for stimulation of cell-mediated immunity. Note that it was initially believed that binding of presented antigen alone was insufficient to trigger T-cell activation. It was thought that co-stimulation with IL-1 was reguired. However, the assay used to detect the co-stimulation was found not to be specific for IL-1 alone. The role of IL-1 as a co-stimulator of T-cell activation is now believed to be minimal at most...

Horseradish peroxidase (HRP) is an extracellular plant enzyme that acts in regulation of cell growth and differentiation, polymerization of cell wall components, and the oxidation of secondary metabolites essential for important pathogenic defense reactions. Because of these essential functions, and also because of its stability and ready availability, HRP has attracted considerable attention.13 It has been involved in a number of applications, such as diagnostic assays,14 biosensors,15 bioremediation,16 polymer synthesis,17 and other biotechnological processes.18 More applications in which HRP catalysis is translated into an electrochemical signal are likely to be developed in the near future. 

Cytotoxicity of extracts was determined by MTT Cell Proliferation Assay [13], a qrrantitative, convenient method for evalrrating a cell population s response to external factors, whether it be an increase in cell growth, no effect, or a decrease in growth dne to necrosis or apoptosis. 

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