The objective of the present work was to study the phenomenon of nucleotide sequence polymorphism in alleles of the STR-loci of human chromosomal DNA and to estimate its interpopulation differences with a view to the search for the molecular-genetic markers to be used as an efficient tool for the determination of belonging of the subjects of interest to a given population. We undertook the comprehensive analysis of amplified DNA fragment sequence polymorphism (AFSP) and amplified DNA fragment length polymorphism (AFLP) with the use of the PLEX-ID-TM analytical mass-spectrometry platform (Abbott Molecular, USA). The interpopulation differences were estimated in terms of the presence or the absence of single nucleotide replacements (SNP) in the STR markers based on a few population samples. Some of the loci of interest were found to have allelic variants the occurrence of which was significantly different in individual samples. Such alleles are of importance for the further investigation since they can be regarded as potential ethno-geographical markers. Their application opens up the new promising prospects for the expert detection of the ethnic affiliation of individual subjects.

The objective of the present pilot investigation was to reveal and to study polymorphism of nucleotide sequence in the alleles of STR loci of human autosomal DNA with special reference to the role of this phenomenon as a source of the differences between homonymous allelic variants. The secondary objection was to evaluate the possibility of using the data thus obtained for the enhancement of the informative value of the forensic medical genotyping of STR loci by means of identification of single nucleotide polymorphisms (SNP) for the purpose of extending their allelic spectrum. The methodological basis of the study was constituted by the comprehensive amplified fragment length polymorphism (AFLP) analysis and amplified fragment sequence polymorphisms (AFSP) analysis of DNA with the use of the PLEX-ID^TM analytical mass-spectrometry platform (Abbot Molecular, USA). The study has demonstrated that polymorphism of DNA nucleotide sequence can be regarded as the possible source of enhancement of the discriminating potential of STR markers. It means that the analysis of polymorphism of DNA nucleotide sequence for genotyping AFLP-type markers of chromosomal DNA can considerably increase the effectiveness of their application as individualizing markers for the purpose of molecular genetic expertises.

The authors overview the current state of research in the field of diagnostics and identification of the signs suggesting the presence of HIV in the materials obtained from the human corpses undergoing forensic medical expertise at different stages of their post-mortem changes. Another objective of the present work was to evaluate the risk of HIV infection for the medical personnel involved in the autopsy studies taking into consideration the significance attached in different countries to the problem of anti-infectious protection of the staff of the state institutions of forensic medical expertise. The authors discuss the possibilities and limitations of the application of the methods for HIV diagnostics, such as immunoenzymatic assays. The special attention is given to the advantages of the molecular genetic methods based on the use of the specific fragments of the viral RNA genome as the diagnostic markers. The solid methodological basis for molecular genetic diagnostics of HIV infection is provided by PCR-amplification with the detection in the real-time regime. It is supposed that this approach will make it possible not only to determine, with the high degree of accuracy and specificity, the presence of the viral genome in the biological materials but also to reduce to a minimum the probability of both false-positive and false-negative responses.