Bioassays
cell toxicity & proliferation assays
G-Biosciences offers a range of non-radioactive assays for the detection of cell toxicity, cell death and cell proliferation that are ideal for high throughput screening. Each CytoScan™ assay is designed for a microwell format and is suitable for studying chemical and cell-mediated cytotoxicity, viability, death or proliferation.
CytoScan™ LDH Cytotoxicity Assay
The CytoScan™ LDH Cytotoxicity Assay is a colorimetric method of assaying cellular cytotoxicity and is an alternative to 51Cr release cytotoxicity assays. The kit combines the advantages of reliability and simple evaluation, characteristic of radioisotope release assays, with the convenience of accuracy and avoidance of radioactivity.
The CytoScan™ LDH Cytotoxicity Assay Kit can be used with different cell types for assaying cell mediated cytotoxicity as well as cytotoxicity mediated by chemicals and other test compounds.
The assay quantitatively measures the stable, cytosolic, lactate dehydrogenase (LDH) 
enzyme, which is released from damaged cells. The released LDH is measured with a coupled enzymatic reaction that results in the conversion of a tetrazolium salt (iodonitrotetrazolium (INT)) into a red color formazan (see figure) by diaphorase. The LDH activity is determined as NADH oxidation or INT reduction over a defined time period. The resulting formazan absorbs maximally at 492nm and can be measured quantitatively at 490nm.
CytoScan™ LDH Cytotoxicity Assay Product Details | Order Online
CytoScan™-fluoro Cytotoxicity Assay
The CytoScan™-fluoro is based on the quantification of cellular lactate dehydrogenase (LDH) released when cells are damaged or under stress. Lactate dehydrogenase released into the culture medium is measured with a diaphorase coupled enzymatic assay that results in the conversion of a non-fluorescent compound (resazurin) to a fluorescent compound (resorufin), which is measured using a fluorometer. The assay detects even low level damage to cell membrane not detected with other methods.
The CytoScan™-fluoro kit does not damage healthy cells and the assay can be performed directly in the cell culture wells containing a mixed population of viable and damaged cells. The kit is supplied with substrate mix, assay buffer, and stop solution.
CytoScan™-fluoro Cytotoxicity Assay Product Details | Order Online
CytoScan™ SRB Cytotoxicity Assay
CytoScan™-SRB Cytotoxicity Assay is an accurate and reproducible assay based upon the quantitative staining of cellular proteins by sulforhodamine B (SRB).
This assay has been used for high-throughput drug screening at the National Cancer Institute (NCI). Sulforhodamine B is an anionic aminoxanthene dye that forms an electrostatic complex with the basic amino acid residues of proteins under moderately acid conditions, which provides a sensitive linear response. The color development is rapid and stable and is readily measured at absorbances between 560 and 580nm. The kit components are sufficient for performing up to 1000 assays.
CytoScan™ SRB Cytotoxicity Assay Product Details | Order Online
CytoScan™ WST-1 Cell Proliferation Assay
CytoScan™ WST-1 Cell Proliferation Assay is a sensitive and accurate assay for cell proliferation and cytotoxicity. The assay is highly convenient as it is performed in a single cell tissue culture well and requires no washing, harvesting or solubilization of cells. Adherent or suspension cells are cultured in a microplate and then incubated with WST-1 and the assay is monitored with a spectrophotometer.
The assay principle is based upon the reduction of the tetrazolium salt WST-1 to formazan by cellular dehydrogenases (see figure below). The generation of the dark yellow colored formazan is measured at 420-480nm (optimal at 440nm) and is directly correlated to cell number. The kit components are sufficient for performing up to 500 assays.
CytoScan™ WST-1 Cell Proliferation Assay Product Details | Order Online
