Introduction of BioChip

Biochip is a miniature version of a laboratory, using which more than hundreds of biochemical reactions take place simultaneously. They are specially designed for functioning in a biological environment, especially inside living organisms. It is not an electronic device. Biochips consist of millions of biosensors, which acts as microreactor used for detecting particular analytes such as an enzyme, protein, biological molecule and antibody.

History :
Biochip development began with the early work on sensor technology. An American company by the name of Affymetrix developed the first biochip, named Genechip which comprises of a number of DNA sensors used for finding defects.

How Does a Biochip Function ?
The biochip has different probes such as DNA, RNAi, protein fragments, etc., which are represented by a point in the chip. These probes bind with the targets present in the sample to be tested. Because of hybridization the contact between the probes and their target is implemented. Biochip scanners and microarray image analysis software are then used for target identification and signal quantification. The results are obtained on a statistical level and are interpreted in a biological context.

Components Of Biochip :
A Biochip comprises of two components, a transponder, and a reader.

(a). Transponder :
Biochips consist of a passive transponder i.e. these transponders require a low electrical charge to activate. The transponder consists of the following four parts

1. Antenna coil – It is very basic and small used for sending and receiving signals from the scanner.
2. Computer microchip – It stores a unique identification number ranging from 10-15 digits.
3. Tuning capacitor – It is charged with a very small signal sent by the operator.
4. Glass capsule – It is made of a biocompatible material specifically soda-lime glass. It is used for holding the antenna coil, capacitor and microchip.

(b). Reader :
It consists of a coil called exciter which is used for creating an electromagnetic field(emf) with the help of radio signals. It provides the required energy to trigger the chip. A receiving coil is present for receiving the transmitted code directed back from the excited implanted chip.

Types :
The following three types of Biochips are available : –

1. DNA Microarray –
   It comprises of a large number of tiny DNA spots which are fixed to a strong surface. It is used to calculate the expression levels for a large number of genes. Each and every DNA mark comprises of probes (the picomoles of a particular gene). Generally, probe-target hybridization is observed and calculated by recognition of fluorophore (a fluorescent chemical compound which can re-emit light upon light excitation) labeled targets to decide the relative quantity of nucleic acid series in the target. Innovative arrays of macromolecule were macro arrays concerning nine cm X twelve cm and also the at the start machine-driven icon-based analysis was revealed within the year 1981.
2. Microfluidic Chip –
   They are a replacement for a biochemical laboratory. They are used for a large number of reactions such as DNA analysis, molecular biology procedures and many more biochemical reactions. These chips are really complex because they contain thousands of components. These parts are designed physically known as a bottom-up full-custom arrange, which may be a terribly giant workforce.
3. Protein Microarray –
   These chips are used to track the activities as well as connections of proteins, and to find out their function on a large scale. Its main advantage is that it can be used for tracking a large number of proteins in parallel. This protein chip comprises a surface for supporting like microtiter plate or bead, nitrocellulose membrane, the glass slide. These are automated, fast, economical, very sensitive, consume less quantity of samples. The first methodology of protein chips was introduced in antibody microarrays of scientific publications in the year 1983. The technology behind this chip was quite easy to develop for DNA microarrays, which have became the foremost generally used microarrays.

Advantages :
Biochips has the following advantages –

• They are very small in size and are powerful and faster.
• It can perform thousands of biological reactions in a few seconds.
• Biochip and help in various diseases.

Disadvantages :
Biochips has the following disadvantages –

• They are expensive.
• They can be fixed inside a human body even without their consent.
• They can raise serious problems of individual privacy.

Applications :

1. The biochip can be used for tracing any human being or animal anywhere in the world.
2. It can be used in various fields such as a BP sensor, oxygen sensor in the medical field.
3. Biochips can be used for storing his personal medical and financial information.