Molecular genetics is on the guard of the law

Abstract

Molecular genetics is one of the key tools of modern medicine. With its help, scientists can study the structure and function of DNA, decode genetic codes, and develop new treatments. In the conditions of the modern world, where global crises, such as the war in Ukraine, occur more and more often, the role of molecular genetics goes far beyond standard medical tasks and becomes critically important for solving social, legal and humanitarian problems. Thus, molecular technologies have become an important tool both in the public health maintenance and in the human rights protection.

Aim. Study and optimization of methods of molecular genetic identification of a person using DNA analysis in forensic practice.

Materials and methods. The study is aimed at evaluating the effectiveness and accuracy of DNA analysis for solving identification tasks, as well as its application in the conditions of complex biological samples, which is important for ensuring the reliability of DNA expertise results in the context of forensics. At the first stage, a cytological examination is performed to identify cells with nuclei, after which DNA extraction is performed using proteinase treatment, phenol-chloroform purification, or the “Chelex” ion exchange resin method. The “Applied Biosystems” 7300 RealTime PCR Systems device is used to assess the quantity and quality of the isolated DNA, which allows to establish the state of the DNA for further analysis by the polymerase chain reaction (PCR) method. With the help of this method, which allows amplification of even minimal fragments of DNA, it is possible to obtain millions of copies of DNA, which enables its further study, even in the presence of trace amounts of biological traces. The obtained data are analyzed using the “Applied Biosystems” 3500 genetic analyzer, which has 8 columns and allows the simultaneous analysis of 8 objects and the four-channel “SeqStudio” genetic analyzer. This method helps to detail the length of DNA fragments and distinguish them by fluorescent labeling, which is used to build a DNA profile and establish kinship or identity.

Results. The results of the study confirm that the use of molecular methods allows achieving high levels of accuracy, reproducibility and reliability of data. This is especially important for complex cases where other methods cannot give the desired result. As a result, molecular technologies of DNA analysis have proven themselves as an effective method that allows not only to identify a person, but also to restore the chronology of events based on micro-traces of traces of biological origin, which significantly increases the accuracy and reliability of examinations, and helps in solving crimes.

Conclusions. The introduction of molecular technology into expert practice allows to perform the analysis of extremely small amounts of nuclear and mitochondrial DNA and thus to achieve the maximum effectiveness of researching the most complex biological objects to date: hair that has fallen out (one of the most frequently recovered objects from crime scenes); bone remains (including exhumed ones); mummified and dried tissues; cells of the epidermis. In the world, forensic DNA analysis is recognized as one of the most promising areas of development of forensic examinations, and its results are currently one of the most reliable pieces of evidence. This proves the relevance of research in the field of molecular biology and genetics, which are aimed at improving the methods of DNA analysis. The relevance of research is also due to the need to increase the accuracy and reliability of the obtained data, which is especially important when working with minimal biological samples or severely damaged materials.