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The results of applying molecular-and-genetic markers of chromosomal DNA in identifying unrecognizable remains of servicemen lost as dead in 1994-1996 and 1999-2001 military campaigns in the Northern Caucuses are summarized in the paper. Some of the specific features related with enzymatic amplification typing of DNA preparations sampled from degraded biological tissues of strongly deformed or decayed cadavers were analyzed. The typing results were analyzed by the AB0 system of degraded expertise samples in order to check the reliability of routine forensic-biological examinations as applicable to cadaver tissues with pronounced putrefactive changes. It was established that group-specific antigens of the AB0 system were correctly determined only in 67.5% of cases. False results were obtained in the other 32.5% of cases. Most of them were related with determination of groups 0(I) and A(II).

The properties of amelogenin amplification system and, in particular, of its species specificity, were studied. DNA preparations extracted from cattle (cow/bull), pig, ram and from poultry (hen), as well as from dog and cat, were used as a matrix for polymerase chain reaction (PCR) involving a standard scheme of enzymatic amplification of the amelogenin gene. It was demonstrated that, unlike for the human DNA, the amelogenin test couldn't be used for the DNA of examined animals as a sex-specific marker. However, there is a danger of a false determination of the male sex in the female origin samples during a forensic-experts' typing of the amelogenin gene, if there is an admixture of an animal DNA to a human DNA preparation. As for the biological samples of the animal origin, there is a possibility of a false-female sex determination. It can be attributed to an incorrectly selected standard of the molecular weight or to its remote location on the gel as well as to the use of an inaccurately calculated algorithm designed for determining the sizes of analyzed fragments.

A possibility was investigated to use the phylogenetic analysis of mitochondrial (mt) DNA to differentiate between the mito-types in mixed subjects in forensic medical examinations. The suggested methodological approach is based on the use of electrophoregram and on the comparison of such data with the information about phylogenic individual (mt) DNA lines.

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.

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.

Until recently, data bases on incidence rates of alleles STR (LPL, vWA and THO1 loci) have not been introduced in Russia. To obtain information on the above rates in Russia, a large scale research of distribution of LPL, vWA and Tho1 loci has been performed among a sample of 442 blood-unrelated persons from 57 regions of the Russian Federation to specify basic assessment characteristics of these loci and to raise efficiency of expert use of identifying systems on their base. Relevant parameters (allele frequencies) are presented for each polymorphic locus as well as basic population characteristics of polymorphism in the studied sample of RF population. These results can be used as key parameters for standard probability estimations in assessing the results of molecular-genetic identification.

This paper presents the first experience gained in Russia in expert identification practice with complex utilization of technologies of molecular genetic individualization of biological objects for solving identification tasks requiring the maximum complete armory of mutually supplementing means. This is particularly important for forensic expert personality identification in cases with many deaths, when indirect identification has to be resorted to, consisting in the use of biological samples from relatives of the victims as the identifying objects. Methodological approaches and concepts of expert studies, used for identification of the remains of people who died in terroristic acts committed in Moscow in September, 1999, are discussed. The results of this study and methodological experience notably extend the potentialities of expert evaluation as regards forensic medical identification of victims of overall disasters, terroristic acts, and war conflicts.

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 Hispanlab firm (Spain) offers a new series of Molecular Screen analytical agarose, including MS-4 agarose intended for separation of small fragments of DNA. This low-endosmotic agarose attracts attention as a probable alternative to well-known FMC Bio Products special agarose (USA) due to its useful properties. We characterized a gel-electrophoretic system based on MS-4 agarose (and its correspondence to its passport) and tested its fitness for standard molecular genetic expert investigations. The following parameters were assessed: mechanical properties of gel, its transparency, degree of background fluorescence upon ethidium bromide staining, resolving power, and position distortions in the electrophoregram. Important features of MS-4 agarose gels were detected, not typical of other agarose systems, which should be borne in mind during investigations with this agarose.