Certain subtypes of acute myeloid leukemia occur as a result of the cooperation of several events these are, the formation of fusion genes as a result of chromosomal rearrangements, which leads to the disruption of cell differentiation, and the emergence of mutations that enhance cellular proliferation by activating intracellular signaling pathways. High-throughput sequencing methods reveal characteristic mutation spectra in leukemia associated with different chromosomal disorders. However, the role of mutation events in malignant cell transformation processes remains obscure. We searched for driver mutation events in leukemic cells containing the chimeric CBFB-MYH11 gene, which results from inversion of chromosome 16. Using target enrichment, the coding regions of 84 genes in genomes of 12 children with acute myeloid leukemia with inv(16) were investigated. Somatic mutations have been found in the genes of the proteins of intracellular signaling cascades mediated by receptor tyrosine kinases, such as KIT (41%), NRAS (25%), KRAS (17%), and FLT3 (8.3%). Comparative analysis of samples at the time of diagnosis and during remission was used to assess the role of mutations in the pathogenesis of the disease. Previously undescribed mutations in the KDM6A, NOTCH1, and IDH1 genes, which may be involved in leukemogenesis processes have been identified.

A comparative study of various approaches to speckle reduction showed that the use of a liquid crystal-based speckle reducer did not allow complete elimination of speckles. The use of mechanical devices for blurring of the speckle pattern in the field of view turned out to be more efficient in the case of quantitative luminescent microscopy. Virtually complete reduction of speckles was observed when a device that combines a ring-shaped fiber-optic light source and a vibration unit that shifts the butt-ends of optical fibers relative to the laser diode during measurement was used. This speckle-reduction approach was successfully used in microarray analysis.

The aim of this work was to compare different speckle reduction techniques. It was shown that the use of devices based on liquid crystals only leads to partial reduction of speckle contrast. In quantitative luminescent microscopy an application of the mechanical devices when a laser beam is spread within the field of view turned out to be more efficient. Laser speckle noise was virtually eliminated with the developed and manufactured mechanical device comprising a fiber optic ring light guide and the vibrator that permits movement of optical fiber ends towards the laser diode during measurements. The method developed for the analysis of microarrays was successfully applied to the problem of speckle reduction.

The biochip was constructed for simultaneous assay of total and free prostate-specific antigen, α-fetoprotein, cancer embryonic antigen, human chorionic gonadotropin, and neuron-specific enolase. These biochips represent an array of gel elements with covalently immobilized proteins. The major analytic characteristics of the developed method were obtained. It was shown that the results of simultaneous assay of six tumor markers in blood serum well correlated with routine measurements of each marker using enzyme immunoassay kits. This approach allowed us to reveal the hook effect of high concentrations during biochip assay, which prevents distortion of the diagnostic picture at high concentration of the analyte in the sample.

Among various factors affecting operation of oligonucleotide microchips, the variations in concentration and in homogeneous distribution of immobilized probes over the cells are one of the most important. The labeling of immobilized probes ensures the complete current monitoring on the probe distribution and is reliable and convenient. Using hydrogel-based oligonucleotide microchips, the applicability of Cy3-labeled immobilized probes for quality control and signal normalization after hybridization with Cy5-labeled target DNA was investigated. This study showed that proper signal normalization should be different in thermodynamic conditions and in transient regime with hybridization far from saturation. This kinetic effect holds for both hydrogel-based and surface oligonucleotide microchips. Besides proving basic features, the technique was assessed on a sampling batch of 50 microchips developed for identifying mutations responsible for rifampicin and isoniazid resistance of Mycobacterium tuberculosis.

A method was developed for producing cell biochips on the basis of calcium alginate. Cell immobilization in microvolumes of nontoxic alginate gel under mild conditions extended the range of testable micro-organisms. The possibility of studying the intracellular processes with alginate gel biochips was demonstrated in model experiments with Escherichia coli, Bordetella bronchiseptica , and Saccharomyces cerevisiae . Cell biochips proved to be suitable for simultaneous monitoring of nucleic acid and protein syntheses with two fluorescent dyes. The effect of chloramphenicol on nucleic acid synthesis was studied with five bacterial strains. Inducible synthesis of the green fluorescence protein (EGFP) in E. coli cells was monitored with the use of biochips. The level of EGFP synthesis correlated with the inductor concentration in the medium.