Biochip (Bioinformatics & Biotechnology)

“Biochips” form the most exciting technology to emerge from the fields of Biotechnology, Electronics and Computers in recent years.
Advances in the areas of proteomics, genomics and pharmaceuticals are empowering scientists with new methods for unraveling the complex biochemical processes occurring within cells, with the larger goal of understanding and treating human diseases.
Almost simultaneously, the semiconductor industry has been steadily perfecting the science of micro-miniaturization.

1. BIOCHIP For BioinfoRmatics and Biotechnology

2. BACKGROUND “Biochips” form the most exciting technology to emerge from the fields of Biotechnology, Electronics and Computers in recent years . Advances in the areas of proteomics, genomics and pharmaceuticals are empowering scientists with new methods for unraveling the complex biochemical processes occurring within cells, with the larger goal of understanding and treating human diseases . Almost simultaneously, the semiconductor industry has been steadily perfecting the science of micro-miniaturization .

3. The merging of these two fields led to the development of Biochip that enabled Biotechnologists to begin packing their traditionally bulky sensing tools into smaller and slighter spaces.

4. DEFINITION Biochip is a collection of miniaturized test sites (microarrays) arranged on a solid substrate that permits many tests to be performed at the same time in order to achieve higher throughput and speed . It is a miniaturized laboratory capable of performing thousands of simultaneous biochemical reactions. Typically, a biochip's surface area is no larger than a fingernail . Like a computer chip that can perform millions of mathematical operations in one second, a biochip can perform thousands of biological reactions, such as decoding genes, in a few seconds.

5. Biochips enable researchers to quickly screen large numbers of biological analytes for a variety of purposes, from disease diagnosis to detection of bioterrorism agent has been extensively studied and developed to enable large-scale genomic, proteomic and functional genomic analyses. A biochip can contain anywhere from tens to tens of millions of individual sensor elements (or biosensors).

6. The packaging of these sensor elements on a solid substrate over a microscopic slide helps in performing lengthy tasks in a short time with high throughput and pace . Unlike microchips, biochips are generally not electronic. Each biochip can be thought of as a “micro-reactor” that can sense a specific analyte. The analyte can be a DNA, protein, enzyme, antibody or any biological molecule.

7. TYPES AND APPLICATION A biochip comprises mainly three types : DNA microarray, protein microarray, and microfluidic chip . With the integration of microarray and microfluidic systems, a micro total analysis system, which is often called a lab-on-a-chip (LOC) system, is produced. Advances of nanotechnology have continuously reduced the size of the biochip which in turn reduced the manufacturing cost and increased the high throughput capability .

8. Due to the benefits of low expense, high throughput and miniaturization, this technology has great potential to be a crucial and powerful tool for clinical research, diagnostics, drug development, toxicology studies, and patient selection for clinical trials. The greatest advantage of the DNA arrays is its speed and high throughput and they are useful in various genomic applications, including single nucleotide polymorphism (SNP) analysis, gene expression studies, disease classification, function prediction, pathway identification, new drug development, clinical diagnostics, and toxicology studies .

9. Protein chips, especially functional microarrays, are used to study basic biological properties like examining protein interactions with other ligands such as proteins, peptides, lipids or other molecules. The most common use of protein microarrays is in immunoassays, and they also played a significant role in the development of safer drugs through the comprehensive profiling of drugs or lead compounds for effects. LOCs are capable of conducting various types of chemical and cellular analysis, separations and reactions .

10. LOC is one of the fastest growing areas of microfabrication and nanotechnology development, integrating many technologies to develop applications in a wide range of disciplines including genetic analysis, disease diagnosis, culturing and manipulating cells, drug discovery, and materials chemistry.

11. Biochips can be categorized into three broad categories based on applications, namely Molecular Analysis, Diagnostics and Non-Biological Usage. Molecular Analysis includes detailed study of different types of molecules such as proteins, DNAs, RNAs, antibodies, antigens, enzymes and pathogens such as bacteria, fungi and viruses. It also includes hybridization of nucleic acids.

12. Diagnostics basically include the use of biochips in medical purposes such as prognosis, treatment and diagnosis of wounds, blood clots and diseases (mainly cancer). Non-biological Usage includes the use of biochips in non-medical fields as organic semiconductors and temperature controllers.

13. COMPONENTS The biochip implant system consists of two components : transponder and reader . The biochip system is radio frequency identification (RFID) based, using low-frequency radio signals to communicate between the biochip and reader . The reading range or activation range, between the reader and biochip is small, normally between 2 and 12 inches.

14. THE TRANSPONDER The transponder is the actual biochip implant. It is a passive transponder, meaning it contains no battery or energy of its own. In comparison, an active transponder would provide its own energy source, normally a small battery . Being passive, it's inactive until the reader activates it by sending it a low-power electrical charge

15. A )Computer Microchip: The microchip stores a unique identification number from 10 to 15 digits long . The storage capacity of the current microchips is limited, capable of storing only a single ID number. AVID (American Veterinary Identification Devices), claims their chips, using a nnn-nnn-nnn format, has the capability of over 70 trillion unique numbers. The unique ID number is “etched” or encoded via a laser onto the surface of the microchip before assembly. Once the number is encoded it is impossible to alter. The microchip also contains the electronic circuitry necessary to transmit the ID number to the “reader”.

16. B )Antenna Coil: This is normally a simple, coil of copper wire around a ferrite or iron core. This tiny, primitive, radio antenna “receives and sends” signals from the reader or scanner. C )Tuning Capacitor : The capacitor stores the small electrical charge (less than 1/1000 of a watt) sent by the reader or scanner, which activates the transponder. This “activation” allows the transponder to send back the ID number encoded in the computer chip. Because “radio waves” are utilized to communicate between the transponder and reader, the capacitor is “tuned” to the same frequency as the reader.

17. d )Glass Capsule: The glass capsule “houses” the microchip, antenna coil and capacitor. The capsule is made of bio-compatible material such as soda lime glass. After assembly, the capsule is hermetically (air-tight) sealed, so no bodily fluids can touch the electronics inside. Because the glass is very smooth and susceptible to movement, a material such as a polypropylene polymer sheath is attached to one end of the capsule. This sheath provide a compatible surface which the bodily tissue fibers bond or interconnect, resulting in a permanent placement of the biochip.

18. THE READER The reader consists of an "exciter" coil which creates an electromagnetic field that, via radio signals, provides the necessary energy (less than 1/1000 of a watt) to "excite" or "activate" the implanted biochip . The reader also carries a receiving coil that receives the transmitted code or ID number sent back from the "activated" implanted biochip.

19. ANALYSIS METHOD The methods used for analysis of the sample include Electrophoresis, Mass Spectrometry, Luminescence, Electrical Signals and Magnetism . Electrophoresis is the motion of dispersed particles relative to a fluid under the influence of a spatially uniform electric field.

20. Mass spectrometry (MS) is an analytical technique that produces spectra (singular spectrum) of the masses of the molecules comprising a sample of material . The spectra are used to determine the elemental composition of a sample, the masses of particles and of molecules, and to elucidate the chemical structures of molecules, such as peptides and other chemical compounds.

21. Luminescence is emission of light by a substance not resulting from heat. It includes fluorescence and phosphorescence . Electrical Signals generated due to various reactions in the biochip are detected and analyzed . Magnetism is used with biomolecules or biomarkers with magnetic properties for qualitative and quantitative analysis.

22. SIZE The size of a biochip is as small as an uncooked rice grain size. It ranges from 2 inches to 12 inches.

23. COST Biochips are not cheap, though the price is falling rapidly. A year ago, human biochips cost $2,000 per unit . Currently human biochips cost $1,000, while chips for mice, yeast, and fruit flies cost around $400 to $500 . The price for human biochips will probably drop to $500 this year. Once all the human genes are well characterized and all functional human SNPs are know, manufacture of the chips could conceivably be standardized. Then , prices for biochips, like the prices for computer memory chips, would fall through the floor.

24. Working of biochip Reader generate a low power electromagnetic field to activate the implanted biochip The biochip sends a unique id t the reader The reader convert the id in to digital format, decodes and displays the id on the number on the LCD display’ This number is compared with a database listing of already registered details

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