[HLA-DQA1, AB0 and AMEL genotyping of biological material by biochips].

A genotyping method of biological material for ABO, HLA-DQA1 and AMEL loci is described. The method is based on allele-specific SNP determination using the hydrogel biochips technology. The amplified fluorescently labeled fragments of the genes were hybridized with specific DNA probes immobilized on a biochip. The allele/genotype assignment was done according to the distribution of fluorescent signal. The minimal amount of biological material is corresponded to 100 pg of DNA. The method was proved using control samples with known genotype. Using biochips 442 DNA samples belonging to the East Slavic population group were genotyped. The allele frequencies of ABO and HLA-DQA1 loci were determined. The possibility of genotyping of biological traces, including the stubs of filter cigarettes, material from the lip of the glass was demonstrated. This method can be used for genetic testing in forensic studies. The probability that the determined genotype belongs to a concrete individual was estimated as 99.6%.

[Typing of ABO locus with biological microchip as a new level in solution of problems in forensic-medical biological expertise of material evidences].

There are cases in practice when during expertise of material evidences, discrepancies between results of typing of ABO antigens and molecular-genetic typing of DNA occur. In this work, as a radical approach to objective solution of similar conflict situations, for some contradictory case of expertise, all examinations were performed on the unified methodological base--DNA level. Instead of biological (isoserological) typing of ABO antigen, molecular-genetic typing of ABO locus with biological microchip was performed. In all cases the results, received with the use of biological microchip, do not contradict but completely conform to the results of others molecular-genetic examinations performed in the case. Given results indicate irrationality of further use of traditional methods of isoserological typing of ABO antigen for primary differentiation of biological material. These analyses, if necessary, have to be performed on DNA level with molecular-genetic expertise.

[Development and application of hydrogel oligonucleotide microchips for forensic-medical personal identification as illustrated by ABO locus].

The article describes the method defining 5 alleles of ABO blood group typing system by molecular hybridization in hydrogel oligonucleotide microchip. The testing points were SNP variants in positions 261 and 297of exon 6 and in positions 646 and 657 of exon 7. Therefore, 5 ABO blood groups can be easily revealed: A, B, 0(1), 0(1v), 0(2). The method was tested on 10 DNA samples isolated from blood and saliva of unrelated individuals. The results were confirmed by sequencing of the identified allelic fragments. Estimation sensitivity was 25 pg of total DNA input. This technique is cost-effective and easy for use and, therefore, promising for forensic-medical personal identification.

[Analysis of chromosome translocations involving MML by hybridization with an oligonucleotide microarray]. / Analiz khromosomnykh translokatsii s uchastiem gena MLL metodom gibridizatsii s oligonukleotidnym mikrochipami.

Identification of chromosome rearrangements is of importance for exact diagnosis, risk assessment, and therapy in blood malignancies. A new method was proposed for rapid and accurate identification of leukemia forms caused by chromosome rearrangements involving MLL (11q23). The method combines reverse transcription-multiplex PCR and hybridization with an oligonucleotide microarray. The microarray was designed to detect the five most common MLL rearrangements: t(4;11) MLL/AF4, t(9;11) MLL/AF9, t(11;19) MLL/ELL, t(11;19) MLL/ENL, and dup(11) MLL/MLL. With clinical specimens, the method was shown to efficiently identify the chromosome translocations in leukemia patients.