Tools and Techniques Used in Forensic DNA Typing

Abstract

The chapter starts with a basic overview of the history of DNA and its use in human identification. Then, it discusses the fundamental information about DNA, its structure, and its function. Further sections of this chapter explain the various techniques used for forensic DNA analysis. It covers the processes involved in the preparation of the samples for DNA amplification through the polymerase chain reaction or PCR methods. Separate sections are dedicated to the explanation of commonly used STR markers, Y chromosome markers for specifically identifying the male contributor of a sample, and mitochondrial DNA, which is maternally inherited and utilized in cases where highly degraded DNA is found. Finally, in the last section, the topic of nonhuman DNA is touched, which describes how the “other” DNA can aid forensic investigations. This DNA examination constitutes the investigation of animal, plant, and microbial DNA testing. The technology portion of the chapter includes the description of the separation of DNA molecules using slab gel and capillary electrophoresis. Fluorescent detection methods are generally used. It also mentions the use of digital DNA databases to solve crimes and identify suspects. It likewise explores issues that are one of a kind to the scientific DNA analysis such as sample mixtures, in particular combinations, debased DNA tests, PCR restraint, and tainted, all of which sway criminological casework since numerous examples don’t come from a sterile, controlled climate. The national DNA information bases that consist of the genetic data will profit the law requirement by connecting various crimes.