DNA profiling: A metrological and signal processing perspective

DNA analysis has gained paramount importance in forensic practice, and its validity cannot be challenged by its imprudent use or by claiming accuracy values that are beyond plausibility. On the contrary, its limitation must be carefully evaluated in a case by case approach, so that it is possible to establish whether the obtained profile is suitable for the intended use. The problems related to the correct use of forensic DNA analysis techniques are well known, and some countries, such as the USA, have started ambitious and comprehensive programs to provide pondered solutions to both the technical and judicial sides of the considered problems. Metrology can give an important contribution, as shown in this article, to both the correct formulation of the problem and its solution. Most of the fundamental points raised are well-known concepts in metrology and may have a satisfactory solution if treated from a correct metrological perspective. Most importantly, the presence of doubt is a familiar concept in metrology, where the doubt about the validity of the results of measurements is considered and quantified in terms of measurement uncertainty. This same concept is extremely helpful in quantifying the doubt of a wrong decision when the decision is based on measurement results, such as DNA analysis. Therefore, the role of metrologists is extremely important in DNA profiling, too, and should be promoted by the instrumentation and measurement community.