“It has long been an axiom of mine, that the little things are infinitely the most important.” Arthur Conan Doyle It was never been thought that the DNA molecule, a little thing, could prove to be possibly the most important source in the crimeinvestigation. Since the onset of DNA fingerprinting, scrutinization of DNA molecules helps in identifying victims of crimes or accidents andconvicts or exonerates the suspects. It inspires the development of new methods in molecular biology, statistical analysis and usage of databases.DNA evidence speaks more than an eye witness.
The word forensic comes from the Latin word forensic which means’ “of or before the forum”. The usage of advanced scientific techniques for the implementation of law during criminal and civil cases to get the solution of important questions about the crime is known as forensic science. It includes both science and law.
Forensic investigation is the use of the tools of science along with exact scientific facts, to help in solving legal problems. All the branches of forensic investigation don’t include biotechnology. For example, the study of fingerprinting or firearms proof does not include biotech. Nevertheless, examination of proof from blood and bodily fluids does depend on biotechnology.
Several types of investigators are applied in these analyses. Crime scene investigators regulate access to the scene to evade any external contamination. Then, they collect evidence for laboratory assessment. The samples must be picked out by avoiding cross-contamination with other evidence on the crime scene. The supervision of this evidence must be closely valued for any typesof poor storage, contamination or tampering. The evidence is then cautiously assessed in a laboratory. Laboratory crime scene investigators evaluate tissues or blood evidence and perform many other experiments to examine the samples collected at the scene.
Forensic methods to categorize someone have progressed from considering a person’s actual fingerprints (looking at the arches and whorls in the fingertips) to analyzing genetic fingerprints. DNA fingerprinting is also called DNA profiling or DNA typing. Though human DNA is 99% - 99.9% identical from one individual to the next, DNA identification devices use the unique DNA to create a unique arrangement for every individual.
Cells in the body, whether collected from cheek cell, skin cell, blood cell, or other tissue share the same DNA. This DNA is exclusive for each individual (except for identical twins who share the same DNA pattern) and thus makes the identification process easywhen two samples are compared.
Just over thirty years ago, Sir Alec Jeffrey’s positioned the foundation stone of modern molecular forensic sciences with the discovery of hypervariable minisatellites and DNA fingerprinting. Before that, accurate human individualization was not possible and the best that could be accomplished by forensic scientists was an exclusion probability grounded on data from gene product analysis of polymorphic blood groups and protein loci or RFLP. In contrast, with the exception of monozygotic twins, DNA fingerprints have the capacity to compare a sample to a unique individual and this capability to possibly individualize altered the mind set of forensic scientists forever. Advancement in forensic investigation has been prompt since the application of multilocus probes, through single-locus VNTR probes and microsatellite loci to arriving approaches including SNPs and proteomic microarrays.