Cell Health Analysis

Cell Viability and Proliferation Assays

Assays for measuring cell proliferation and viability are used to monitor the response and health of cells in culture after treatment with various stimuli. The appropriate choice of an assay method depends on the number and type of cells to be assessed, as well as the expected outcome. Cell proliferation assays may monitor the number of cells over time, the number of cellular divisions, metabolic activity, or DNA synthesis. Cell counting using viability dyes such as trypan blue or calcein-AM can provide both the rate of proliferation as well as the percentage of viable cells. 5(6)-Carboxyfluorescein diacetate N-succinimidyl ester (CFSE) (21888, SCT110) is a popular choice for measuring the number of cellular divisions a population has undergone. Upon entering the cell, CFSE is cleaved by intracellular esterases to form the fluorescent compound, and the succinimidyl ester group covalently reacts with primary amines on intracellular proteins. On each division, the fluorescence intensity of each daughter cell is halved, enabling the simple detection of the number of cell divisions by flow cytometry.

Cytotoxicity Assays

Assays that measure metabolic activity are suitable for analyzing proliferation, viability, and cytotoxicity. The reduction of tetrazolium salts such as MTT and XTT to colored formazan compounds or the bioreduction of resazurin (R7017, TOX8) only occurs in metabolically active cells. Actively proliferating cells increase their metabolic activity, while distressed cells such as those exposed to toxins will demonstrate decreased activity.

Apoptosis Assays

Cell death is necessary for many normal physiological functions in the course of both development and homeostasis. The capacity for tumor cells to elude programmed cell death, also known as apoptosis, is a hallmark of most types of cancer. A wide variety of cellular proteins, including cell surface receptors, adaptors, proteases and mitochondrial components, regulate a fine balance between cell survival and death by apoptosis. Thoughtful assay selection can help to analyze not only the effects of cell culture conditions and treatments on cell health, but the mechanisms by which they affect cell health. We provide a complete range of assay products for early, mid and late stage apoptosis detection.

Cell Contamination Detection and Elimination

The maintenance of contamination-free cell cultures is fundamental to cell-based research. Among the most pervasive cell culture problems is contamination with mycoplasma, a genus of bacteria whose morphology is characterized by sub-micron size and the absence of a cell wall, making these bacteria difficult or impossible to detect by microscopy and resistant to many antibiotics. Although mycoplasma do not usually cause cell death, they are responsible for a variety of effects on cultured cells that includes dysregulated metabolism, reduced proliferation, and chromosomal aberrations. In short, mycoplasma contamination compromises the validity of affected cell lines for providing meaningful data for life science research.