DNA CHIP TECHNOLOGY

Usporedno s razvojem DNA molekularnih markera kao ishodišnih tehnologija analiza DNA, 90-tih godina prošlog stoljeća znanstvenici su počeli razvijati novu tehnologiju nazvanu DNA-čip. Naziv dolazi od toga što se, tehnički gledano, na maloj staklenoj površini nalaze oligonukleotidni lanci poznatog slijeda baza, što podsječa na elektronički čip. Ostali nazivi koji se spominju u literaturi su: biochip, DNA microarray, gene array, gene chip i drugi. Prema namjeni eksperimenata razvijena su tri glavna tipa DNA-čipa: sekvencijski čip, ekspresijski čip i čip komparativne hibridizacije. Osnovna podjela DNA-čipova na oligonukleotidne i cDNA (komplementarna DNA) proizlazi iz njihove svrhe i načina korištenja. Identifikacija mutacija i DNA varijacija na cjelokupnom genomu te sekvenciranje i analiza genoma može se izvesti oligonukleotidnim DNA-čipom, dok se cDNA-čip najčešće koristi u proučavanju ekspresije gena, detekciji određenih proteinskih komponenti u hrani, detekciji mutiranih gena, te pri određivanju sigurnosti konzumiranja GMO biljaka. Važnim područjem korištenja DNA-čipa smatra se analiza genske ekspresije i otkrivanje polimorfizma na razini nukleotida (SNP - Single Nucleotide Polymorphisms).Concurrently with the development of molecular markers as the basic technologies of DNA analyses, scientists started to develop new technology, called DNA-chip. The name cames from the technical aspects of the chip, which consists of the small glass plate with attached oligonucleotide strains of DNA on it and looks similar to electronic chip. The other names found in literature are biochip, DNA microarray, gene array, gene chip and others. According to the experimental purpose of the chip, three main types of chips have been developed: sequential chip, expressional chip and chip of comparative hibridization. The basic classification of DNA-chips into oligonucleotide chips and cDNA chips is based on their purpose and the way of use. Detection of mutations and DNA variations in complete genomes, and sequencing and analysis of a genome may be performed with oligonucleotide DNA-chip, while cDNA-chip is mainly used in research of gene expression, detection of particular protein components in food, detection of gene mutations and assessment of biosafety in consuming GMO plants. An important field of application of DNA-chip is analysis of gene expression and detection of variations on the level of nucleotides (SNP - Single Nucleotide Polymorphisms)