Some practical notes about performing polymerase chain reaction and electrophoretic fractionation of amplificated products

Practical aspects concerning standardization of molecular-genetic expertise performing with the use of the method of DNA are considered. Examples of difficulties, which can occur at nonobservance of requirements of polymerase chain reaction and electrophoresis performing, are described; practical recommendations of their elimination are given.     

Optimization of the biological microchip for genotyping of the AB0 locus: correction of DNA probes

The objective of the present work was to search for methodological options facilitating the improvement and optimization of the biological microchip designed for genotyping of the AB0 locus. Testing a prototype biological microchip for genotyping of the AB0 locus using a reference set of preparations with the known group specificity has demonstrated that the choice of DNA probes by theoretical calculation of their thermodynamic parameters does not necessarily yields the desired practical result. Suffice it to say that under certain conditions some cells of the biochip appear to generate artifact hybridization signals that tend to make the results of genotyping either incorrect or difficult to interpret. This problem required the adjustment of the molecular structure of DNA probes for the optimization of their hybridization properties. As a result new DNA probes have been developed and synthesized and new variants of the prototype biochip constructed to be subjected to experimental verification.     

Analysis of genetic diversity of the mitochondrial DNA in the forensic medical expert identification of individuals

Spectra of haplotype frequencies were studied for locuses of hypervariable segments 1 and 2 (HVS1 and HVS2), separately for each, and for linked segment HVS1-HVS2. The obtained data were used to determine the values and to evaluate comparatively the discriminating characteristics of the corresponding individualizing systems based on the typing of mtDNA. The system of typing, based on HVS2 (mv = 0.098), was found to possess the least discriminating potential; while the highest information rate is ensured in the analysis of HVS1 (m omega = 0.02) and in the joint analysis of HVS1 and HVS2 (mw = 0.007). The frequency rates of the key haplogroups were estimated within a random sampling of Russian citizens. A random population sampling of Russian citizens was shown not to differ essentially from an ethnically homogeneous population sampling of Russians selected with regard for a genetic diversity and for a spectrum of mitochondrial lines. The results point at the most rational algorithm of examinations in a forensic expert's analysis of mtDNA. The studied sampling can trigger the development of a referential data base designed for conducting, in the Russian Federation, the forensic-medical expert's examinations based on the mtDNA typing.     

Mitochondrial DNA typing--a new level for solving identification problems in forensic medical expert identification of unidentified remains of victims of terrorist acts in Moscow and the armed conflict in the Chechen Republic

Two large-scale episodes described in this paper reflect the first in Russia use of molecular genetic matrilinear markers (analysis of polymorphism of sequences of amplified fragments of mitochondrial DNA hypervariable locuses) in solution of a complex identification problem: forensic medical identification of unidentified fragments of victims of explosions of houses in Moscow in September, 1999, and of soldiers dead in the war conflict in the Chechen Republic in 1994-1996. The results of this work and methodological experience gained in it essentially extend the potentialities of expert studies as regards forensic medical identification of victims of large scale disasters, terroristic acts, and war conflicts.     

The experience of using the FTA-carriers for blood sample storage while conducting the molecular-genetic identification of unidentified killed persons--victims of military actions in the territory of the Chechen Republic

The activity of adapting and introducing the FTA-carriers for the storage of blood samples of relatives of missing service men for the purpose of using them in the consequent identification measures in respect to non-identified killed persons has been conducted in the Russian Federation within the framework of identification of service men killed in the Chechen territory during the 1994-1996 armed conflict. The article generalizes the experience of practical usage of FTA-cards as an element in the technological sequence of the molecular-genetic identification expertise. Methods related with application of FTA-technologies were tested; the efficiency of polymerized chain reaction was evaluated by using the matrix of immobilized DNA for hypo variable segments HVS-1 and HVS-2 as well as for the D-loop of mitochondrial DNA and for chromosomal STR-locuses D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317 and D7S820.     

Combined use of molecular genetic technologies to identify the Russian citizens died during tsunami in Thailand

Main stages, methodological aspects and practical results of molecular genetic research to identify the citizens of Russia died during tsunami in Thailand are considered.