1 Chemical Mutagens and Sister-Chromatid Exchange.- 1. Introduction.- 1.1. Advantages of Studying Sister-Chromatid Exchange.- 1.2. Development of Modern Techniques.- 2. Sister-Chromatid Exchange as a Measure of Chromosome Damage.- 2.1. Variation in the Baseline Frequency of Sister-Chromatid Exchange.- 2.2. Induction of Sister-Chromatid Exchanges by Ultraviolet Light, X Rays, and Viruses.- 2.3. What Are Sister-Chromatid Exchanges?.- 2.4. Factors That Affect the Frequency of Sister-Chromatid Exchanges Induced by Chemicals.- 3. Systems and Methods t2.- 4. Summary.- 5. References.- 2 Modification of Mutagenic Activity.- 1. Introduction. 41 2. Factors That Influence Metabolic Activation t2.- 3The Detection of Chemical Mutagens/Carcinogens by DNA Repair and Mutagenesis in Liver Cultures.- 1. Introduction.- 2. Types of Chemical Carcinogens.- 3. Metabolic Activation Capability of Liver.- 4. Liver Cultures.- 4.1. Hepatocyte Primary Cultures.- 4.2. Long-Term Epithelial Cultures.- 5. Carcinogen Metabolism in Liver Cultures.- 6. Hepatocyte Primary Culture/DNA Repair Assay.- 6.1. Autoradiographic Assay.- 6.2. Liquid Scintillation Counting Assay.- 7. Mutagenesis of Rat Liver Epithelial Lines.- 8. Hepatocyte-Mediated Mutagenesis of Rat Liver Epithelial Lines.- 9. Discussion.- 10. References.- 4 Commercial Screening of Environmental Chemicals.- 1. Introduction.- 2. Transfer of Technology.- 3. Goals of Genetic Toxicology in Chemical Safety Evaluation.- 3.1. Approaches for Assay System Deployment in the Identification of Genotoxic Substances.- 3.2. Application of Test Results to Health and Safety Considerations.- 3.3. Application of Test Results to Management Decisions Concerning Chemical Development.- 4. Technical Operation Requirements.- 4.1. Facilities.- 4.2. Data Management and Control.- 4.3. Chemical Storage and Waste Disposal.- 5. Legal Operation Requirements.- 5.1. Laboratory Safety and Employee Monitoring.- 5.2. Good Laboratory Practices and Guidelines.- 6. Summary.- 7. Referlc<