CONTENTS 54. Solid-Phase Extraction for Preconcentration 45 5.5. Sample Preparation for Water Samples 5.7. Preparation of Sample Slurries for Direct AAS Analysis 5.8. Hydride Generation Methods 59. Colorimetric methods 5. 10. Metal Speciation 5. 10.1. Types of Speciation 5. 10.2. Speciation for Soils and Sediments 5.10.3. Sequential Schemes for Metals in Soil or sediment 5.10.4. Speciation for Metals in Plant Materials 5. 10.5. Speciation of Specific Elements 5.11. Contamination during Metal Analysis 5. 12. Safe Handling of Acids References SECTION B SAMPLE PREPARATION FOR NUCLEIC ACID ANALYSIS CHAPTER 6 SAMPLE PREPARATION N DNA ANALYSIS Satish parimoo and Bhama parimoe 6.1 dNA and its structure 6. 1. Physical and Chemical Properties of 6.1. 2. Isolation of dNa 6.2. Isolation of dna from bacteria 6.2. 1. Phenol Extraction and Precipitation of dNa 278 6.2.2. Removal of Contaminants from 63. Isolation of plasmid dna 6.3. 1. Plasmid DNA Preparation 6.3. 2. Purification of plasmid dNa 285 64. Genomic DNA Isolation from Yea5.4. Solid-Phase Extraction for Preconcentration 245 5.5. Sample Preparation for Water Samples 248 5.6. Precipitation Methods 251 5.7. Preparation of Sample Slurries for Direct AAS Analysis 251 5.8. Hydride Generation Methods 252 5.9. Colorimetric Methods 254 5.10. Metal Speciation 255 5.10.1. Types of Speciation 257 5.10.2. Speciation for Soils and Sediments 258 5.10.3. Sequential Schemes for Metals in Soil or Sediment 259 5.10.4. Speciation for Metals in Plant Materials 260 5.10.5. Speciation of Specific Elements 262 5.11. Contamination during Metal Analysis 263 5.12. Safe Handling of Acids 264 References 264 SECTION B SAMPLE PREPARATION FOR NUCLEIC ACID ANALYSIS CHAPTER 6 SAMPLE PREPARATION IN DNA ANALYSIS 271 Satish Parimoo and Bhama Parimoo 6.1. DNA and Its Structure 271 6.1.1. Physical and Chemical Properties of DNA 274 6.1.2. Isolation of DNA 276 6.2. Isolation of DNA from Bacteria 278 6.2.1. Phenol Extraction and Precipitation of DNA 278 6.2.2. Removal of Contaminants from DNA 282 6.3. Isolation of Plasmid DNA 283 6.3.1. Plasmid DNA Preparation 284 6.3.2. Purification of Plasmid DNA 285 6.4. Genomic DNA Isolation from Yeast 287 xii contents