[The characteristics of the enzymatic amplification of locus D17S5 alleles: the need to assess the stability of the amplification profile].

Amplification behavior of one chromosome locus (D17S5), widely used in identification studies, is investigated. The effect of preferable amplification of alleles, characteristic of this locus, often leads to an erroneous conclusion about homozygosity. Our studies showed, that along with the hazard of typing false homozygotes in analysis of locus D17S5, more intricate cases with genotype distortion can occur in expert practice, which may be characterized not only by partial loss of the true alleles, but even by amplification of nonspecific (nonallele) fragments simulating the false-heterozygotic allele profile.

[A method for differential cytolysis in the molecular genetic expert identification of material evidence: problems in optimizing the procedure].

The authors discuss the problem of selective derivation of the genetic material of spermatozoa for molecular genetic identification from mixed biological traces containing sperm on material evidence. Possible methods of improving the efficacy of differential lysis of cells present in mixed traces are analyzed. Effects of some routinely used extractants on biological substrata, most often contaminating the sperm in expert material, have been studied, and conditions for their most complete elimination from objects of investigation optimized.

[The analysis of DNA amplified fragment length polymorphism in forensic identification expertise: the possible sources of errors under nonoptimal conditions for the polymerase chain reaction].

Analyses the effects of nonoptimal conditions of polymerase chain reaction concerning the initial amount of matrix DNA and duration of its amplification on the amplification picture of hypervariable tandem-arranged locuses of human genome. Shows the causes of its possible ambiguous interpretation leading to inadequate expert conclusions in forensic gene-identification expert evaluation. Outlines the approaches to solution of this problem.

[A molecular genetic approach to the forensic medical expertise of biological relationship at the early stages of embryonic development].

A new approach to the identification of a father at the early stages of embryonal development has been developed, validated, and successfully tried. This approach, based on molecular genetic analysis of multiallele loci of human genome using polymerase chain reaction is completely justified and advisable for the relevant expert evaluations.

[The restrictase analysis of human DNA as a method for determining genetic sex in forensic biological expertise].

In this article phenomena related to sex heteromorphism of restrictase hydrolysates of DNA, isolated from objects of expert analysis was recommended for use. The performed investigations allow one to work out the system of discriminating sex of biological objects, based on restrictase analysis of human DNA and on registration of sex-specific restrictase fragments. Possibilities of method and its value for gene-identification expertise were illustrated using certain cases from expert practice.