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Cytotoxicity Screening – XTT Assay
Drug discovery screening for cytotoxicity can identify agents which may be suitable for development as anti-cancer drugs. For other therapeutic targets, however, cytotoxicity interferes with the performance of screening assays which rely on viable cells. Cytotoxicity screening provides a vital tool to eliminate test agents that may generate false positives through their toxic activity.
Assay Principles
This assay is based on the cleavage of the yellow terazolium salt (XTT) by metabolically active human cells (HeLa) to form an orange formazan dye. This conversion only occurs in viable cells, so cytotoxicity leads to a loss of activity. The formazan dye formed is soluble in aqueous solutions and is directly quantified using a scanning multiwell spectrophotometer. This ensures a high degree of accuracy and enables on-line computer processing of the data. Thereby allowing a rapid and convenient handling of a high number of samples.
Results
Cell viability is calculated as a percentage relative to standard controls. Results are reported, summarised graphically, in a format agreed with the client. The assay is suitable for the performance of dose-response studies.
Figure 1. Viability of HeLa cells treated with controls and test agents.
Percentage viability relative to untreated control cells ± SEM
Sample Submission
Samples can be submitted to GlycoMar by prior arrangement, in a number of formats.
Pricing is dependant on sample numbers submitted and turnaround required. Currently the assay is available in a 96-well microplate format offering low – medium throughput.
Standard turnaround is 2 weeks from receipt.
Please contact GlycoMar directly for a quotation, or to discuss your individual requirements:
Tel: +44 (0) 1631 559 368 E-mail: info@glycomar.com
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