How DNA Chip works? Fact File 42

Electronics is emerging as a new branch called Bionics in combination with biology since there are possibilities to explore the ideas from living organisms. Micro organisms are now considering as the major source for developing DNA chips, Molecular switch etc. This new field is the Synthetic biology.

The DNA chips opened a new era in medical research and medical diagnostics. The DNA chip can provide large quantity of genomic data of microorganisms in a few hours, so that identification of the microbe is very easy. A DNA chip is a” Micro array” of genes attached at fixed locations on a solid support like glass slide or silicon membrane.

The chip has microscopic DNA spots that allow massive genetic analysis. The DNA chip works on the principle that the complementary nitrogen bases of DNA join together. A hypothetical DNA chip with 8×8 squares containing a total of 64 squares. If 3 nucleotides are put in each square, then there will be a total of 64 sequences each having 3 nucleotides. If a DNA segment of unknown sequence with 3 nucleotide is rolled over the DNA chip, it will’ stick’ to the sequence in the chip complementary to it. So it is easy to identify the unknown base sequence.

DNA Chips have many applications such as Gene profiling, Comparative gene hybridization, Single-nucleotide polymorphism and Genome sequence analysis. Silicon based DNA Chips are now used in DNA Micro array hybridization. DNA Chips have emerged as a tool for detecting human genetic diseases and disease causing pathogens. There are more than 125 companies engaging in DNA Chip design and development. The manufacturing process involves many electrochemical, chemical and photolithic processes. This makes the DNA Chip development costly.