DNA (deoxyribonucleic acid) is the hereditary material in humans and almost all other organisms. DNA sequencing is a common and requisite practice for molecular biologists today working in all areas of biology, including microbiology. This book aims to provide clues for DNA sequencing projects directed to unsequenced organisms in which many transcripts wait to be discovered, either coding small RNAs or genes homologue to known genes coding for protein products. This book also looks at the adoption of the polymerase chain reaction (PCR) to generate DNA profiles from minute biological samples, and the use of mitochondrial DNA to obtain information from old bones and the applications of Y chromosomal polymorphisms in sexual assault cases. Present research focuses on genetic markers for external visible traits and on improving the utility of poor quality samples with degraded DNA. The other direction of forensic DNA research addresses the difficulty of obtaining a DNA profile in a degraded crime stain. The third topic covered in this book is DNA chips- a microchip that holds DNA probes that form half of the DNA double helix. This book examines the development of DNA chips, as the prototype for global technology genetics.