A Guide to the Russian Academy of Sciences - University of Texas ...

month-long working visits which resulted in obtaining some very important new
results and essential general progress in the SHOM research. At the current state of
SHOM development, our work is focused on the following crucial tasks:
-manufacturing of microchips bearing thousands of immobilized oligonucleotides;
-various methods for preparing fluorescently labeled DNA and RNA probes followed by
their hybridization with oligonucleotides microchips;
-measuring simultaneously the hybridization data from thousands of microchip elements by
means of a specially devised fluorescent microscope.
Within the scope of our interests are also various potential applications of SHOM,
including identification of genetic mutations, gene polymorphism studies,
identification in probes of both known and unknown microorganisms, quantitative
expression studies of genes aimed at partial and full sequencing and mapping of
DNA, manufacturing of "immunomicrochips". Recently we have constructed an
improved version of our robot for manufacturing microchips with immobilized
oligonucleotides. At present, the robot performs 300 acts of application of a drop of
oligonucleotide solution per hour, with further improvement the productive capacity
of the robot should increase upto 6000 applications per hour. In 1995 we developed
a number of chemical procedures for fluorescent labeling of DNA and RNA. An
efficient new method has been worked up for micromatrix preparation by
photopolymerization of polyacrylamide gel. We are working up a CSH technique
which enables one to "elongate" the effective hybridization length of the
immobilized oligonucleotide by means of so-called "contiguous stacking
hybridization" (CSH) whereby DNA is additionally hybridized to one or two
fluorescently labeled pentanucleotides that stack with the immobilized
oligonucleotide to form an extended duplex. An experimental procedure has been
suggested which allows to use effectively iust five rounds of additional
hybridization with pentamers containing all four bases (A, C, T, G) or a single
universal base with differently positioned oligonucleotides marked by different
labels instead of very cumbersome stacking hybridization with all possible (=1024)
pentamers. High efficiency of SHOM has been demonstrated for medical
diagnostics of hereditary diseases and for gene polymorphism studies. We have
also manufactured first mircoorganism-specific microchips and worked out a
SHOM-based procedure which allows to identify microorganisms. The following
patent applications were filed at the US Patent Office on April, 7:
1. A method for preparing matrices to detect mismatches by G. M. Yershov, A. D.
Mirzabekov et al.
2. Method for immobilizing water-soluble bioorganic compounds onto a capillary-porous
carrier by G. M. Yershov, A. D. Mirzabekov et al.
3. Method and device for microdispensing of aqueous solutions of substance onto a carrier
by G. M. Yershov, A. D. Mirzabekov et al.
1997 update: STRUCTURE AND FUNCTION OF CHROMATIN
Head Vadim L. Karpov, Ph.D., D.Sc., Professor
In 1995 we continued our study on mapping and identification of nonhistone proteins along
the yeast genome. Using the method of DNA-protein crosslinking in vivo we
detected two polypeptides that most probably correspond to core subunits of yeast
RNA-polymerase II in the coding region of the transketolase gene (TKL2). Several
non-histone proteins were detected which bind to the upstream region of TKL2,
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