A DNA biochip that is used to measures the expression levels of large numbers of gene fragments immobilized in an orderly pattern and used to monitor the activities of thousands of genes at the same time.
DNA microarray contains picomoles of a specific DNA sequence known as probes which are synthesized and attached via surface engineering to a solid surface through covalent bond to a chemical matrix. It detects single nucleotide polymorphisms or targeted sequence. Microarray differs in working, efficiency, accuracy, fabrication and cost as well as design and methods of analyzing the data.
DNA microarray main principle is the hybridization between two DNA strands to specifically pair with each other by forming hydrogen bonds between complimentary nucleotide base pairs wherein a high number of these base pairs means tighter non-covalent bonding between the two strands.
DNA microarray composed of three experimental design that ought to be considered when designing experiment first, replication of the biological samples is important for drawing conclusions, second replicates must ensure precision and third, spots of each DNA clone are present as replicates to give measures of technical precision in each hybridization.