DNA analysis is the process in which genetic sequences are studied. It is used by law enforcement and medical personnel to identify a particular person or species.
Recent recombinant DNA technology has provided some novel and powerful methods for forensic science application. Human genomic DNA can be analyzed directly for individual identification and paternity testing on the basis of variations in its sequence. The analysis of DNA isolated from forensic biological evidence provides valuable information relating to the identification of the source of the sample. Restriction fragment length polymorphism (RFLP) testing, using a combination of single locus probe (SLP) that vary highly among individuals, produces a DNA fingerprint or profile. The PCR method using STR (microsatellite) and mitochondrial DNA analysis (mtDNA) is suitable for examination of the forensic biological samples (bloodstains, hairs, seminal stains, bones, tooth). For sex identification of bloodstains, bleached skeletons and teeth, Southern blot hybridization with Y-chromosome specific probe (pHY10; 3.4 kb) and PCR amplifying with sex chromosome specific fragments, can be used.
The DNA is analysed through the telomere, with blood samples and finger prints to assess whether that individual committed a crime or is the father of a baby in a rape or paternity suit. This is used in forensics to solve murder cases just by matching the DNA of a person to the DNA at a crime scene.
DNA analysis is used in forensics for establishing identity and in paternity disputes. Another is in assault and sexual offences. With PCR technique a minimal amount of sample is required to extract DNA hence all biological samples from crime scene is preserved for study.