Analyzing Toxicity to Mammalian Cells by Flow Cyometry

Our Phase I research program is based on years of research which strongly suggest that high speed f(FCM) is a technology that can significantly improve toxicity assays. Highly reliable clastogen andhave been developed in our laboratories where FCM has played a major role in processing and analyzinfollowing exposure. In both cases, a significant improvement over conventional assays has resulted.Phase I is to validate both the FCM-based micronucleus assay and the FCM-based tumor promoter assay,stage in Phase I for the development of an FCM-based mutation assay. Thus, an aim is to provide reliassays that offer a significant advance over existing methods by focusing on and quantitating specifreflect a toxic response. Validation of the FCM-based micronucleus assay for detecting clastogenic astarting point for this research program. The conventional micronucleus assay is costly, labor intennumbers of animals and provides marginal statistics. Too few cells are usually scored by hand, and vslides is highly subjective. We will demonstrate how an FCM-based micronucleus assay can reduce costsamples in a shorter time, reduce the number of animals needed while vastly improving the statisticsto the highly subjective nature of hand counting, flow cytometry provides an objective method for evof micronuclei in blood cells. Methods have been developed in our laboratory which accurately scoreerythrocyte population at rates exceeding 10,000 cells/second so that cells are being processed at lthan hand counting. Since all of the development work has involved a few select chemicals, one aim oprogram will be to expand the battery of clastogens and spindle poisons that have been screened within order to demonstrate the general applicability and validity of the method. Similarly, as a resultdeveloped an FCM-based method for screening tumor promoters. These epigenetic agents are invisible itoxicology tests, yet promoters play a major contributory role in the process of neoplastic transforpass through conventional short term in vitro genetic toxicology screening, and the first evidence tpromoter is typically the occurrence of tumors in animal studies. Reliable in vitro assays for detecreduce costly animal experiments by permitting the evaluation of promotional activity earlier in proanother aim of Phase I will be to validate the FCM-based tumor promoter assay that has been develope