In Vitro Genotoxicity Screen Assay: Unscheduled DNA Synthesis Test by Using Flow Cytometry (FL-UDS)

MB Research Laboratories has developed FLUDS, a non-radioactive Unscheduled DNA Synthesis Test using flow cytometry in various mammalian cells to detect DNA damage/repair caused by the genotoxic properties of test substances.

Regulatory agencies require genotoxicity/mutagenicity testing to classify pharmaceuticals, industrial chemicals, and consumer products for cell mutagenicity as well as for carcinogenicity.

Although Unscheduled DNA Synthesis test is one of the recommended genotoxicity assays, involvement of radioactive material and subjective interpretation limited its application. FLUDS, developed by MB, overcomes these limitations and makes Unscheduled DNA Synthesis test a routine genotoxicity assay.

  • FLUDS uses the flow cytometry technique, 5-bromo-2'-deoxyuridine (BrdU) and its antibody to detect the newly synthesized DNA caused by genotoxins, thus eliminating the need for radioactive 3H-thymidine or 32P-nucleotides.
  • Flow cytometry technique allows FLUDS to analyze thousands of target cells in few seconds.
  • FL-UDS uses flow cytometry gated on the G0/G1-phase cells to analyze Unscheduled DNA Synthesis according to the DNA profile (Propidium Iodide staining), rather than a subjective evaluation of S-phase cells by comparing the grain intensity under a microscope.
  • FL-UDS avoids animal use.
  • FL-UDS has 90% accuracy, 100% sensitivity, 85% specificity, 80% positive predictivity and 100% negative predictivity in determining direct-acting genotoxic agents in human keratinocytes, as determined by our validation.

Please contact MB Research, or call 215-536-4110, for further information.

Posters/Presentations

Flow Cytometry-based Unscheduled DNA Synthesis (FL-UDS). G. L. DeGeorge, E. Yurkow, M. Akbar, C. A. Kirk, D. R. Cerven. American College of Toxicology Annual Meeting, 2004.

A High-Throughput Unscheduled DNA Synthesis (UDS) Assay Using Flow Cytometry. C. A. Kirk, D. R. Cerven, G. L. DeGeorge. The Toxicologist 84(1): 452, 2005.

Validation of a Non-Radioactive Flow Cytometry-based Unscheduled DNA Synthesis (FL-UDS) Assay, C. A. Kirk, M. K. Reeder, T. L. Ripper, B.Bowen, M. Fischl and G. L. DeGeorge. American College of Toxicology Annual Meeting, 2005.

Validation of a Non-Radioactive Flow Cytometry-based Unscheduled DNA Synthesis Assay (FL-UDS), C. A. Kirk, M. K. Reeder, T. L. Ripper, G. L. DeGeorge. The Toxicologist 90(1): 115. 2006.

Validation of a Non-Radioactive Flow Cytometry-based Unscheduled DNA Synthesis (FL-UDS) Assay, C. A. Kirk, M. J. Iatropoulos, G. L. DeGeorge, G. M. Williams. Society of In Vitro Biology Annual Meeting, 2006.

A Non-Animal-Based, High-Throughput Unscheduled Dna Synthesis (HT-UDS) Assay For Screening Of Genotoxins. C. A. Kirk, J. Tao, B. Bowen, M. J. Iatropoulos, G. M. Williams, G. L. DeGeorge. The Toxicologist 96(1): 344, 2007.

An Improved Flow Cytometry-Based Unscheduled DNA Synthesis (UDS) Assay. J. Tao, C. Kirk, L. F. Pratt, G. W. Williams, G. L. DeGeorge. The Toxicologist 102(1): 466, 2008.

An Improved Flow Cytometry-Based Unscheduled DNA Synthesis (UDS) Assay. J. Tao and G. L. DeGeorge. American College of Toxicology annual meeting, 2008.

Assessment Of Ultraviolet Light- And Chemical-Induced UDS In Various Cell Lines Using Flow Cytometry. J. Tao, W. Newhard, D. R. Cerven and G. L. DeGeorge. The Toxicologist 108(1): 397, 2009.

The project described above was supported by grant number R44-CA-113243-02 from the National Cancer Institute (NCI), National Institutes of Health (NIH). Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NCI or NIH.

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