Immobilization of Reconstituted Bacteriophagelambda DNA on the Solid Support

Author Name(s): *Alice Jayapradha Cheekurthy ,Prof. C. Ram Babu
Author Email: calicejaya@gmail.com

Abstract

The world of life science research has changed dramatically over the past decade. Researchers now rely on miniaturized systems with tiny cards or chips that contain virtual laboratories on a microscopic scale. Results are achieved in minimum time using smaller amounts of reagents. The use of life processes and materials was perfected in millions of years by nature for bioengineering, to develop devices for following applications to improve quality of human life. This is the latest area of Research and Development. DNA, the blueprint of life, has taken centre stage in biological research during the past few decades. The precise positioning of micro structured surfaces is of immense importance for the realization of Bio-MEMS and Bio-nano-devices. Bacteriophage lambda has been used for the current research work. The current work aimed to view and study the functioning of genetic material in vitro by Immobilization of double stranded DNA on a solid support, here Gold plated silicon wafer and gold plated microelectrode plates are used as solid surface. The work explored the key factors that influence oligonucleotide DNA assembly and surface occupancy behavior and the interferences involved during the covalent binding of reconstituted thiol tethered double stranded Bacteriophage Lambda DNA on the surface of gold microelectrodes. Atomic Force Microscope (AFM) was used to study the affect of cleaning on the surface of gold.

KeyWords

DNA (DeoxyriboNucleic Acid), Bacteriophage lambda,Bionanodevices.

Introduction

Among the myriad of biomolecules nucleic acids play key role in sustaining life. As a genetic material it directs all the processes of life in a very systematic manner with high fidelity. Nucleic acids like proteins are essential for life. It is genetic material in all forms of the living organisms. The term nucleic acid comes from the fact that they are found in nucleus referring to both RNA and DNA. The discovery of DNA is one of the outstanding milestones in the biology because it finally solved the problem of how the living organisms store the information necessary to control the activities of life and pass this information to subsequent generations. Biological function of DNA is to code for proteins that are expressed in the form of genetic information. With the advent of technology Scientists are trying to assign a new role to DNA which nature has never intended for this molecule.
Bacteriophage Lambda: Bacteriophage Lambda is extensively studied virus, a temperate phage of E.Coli, an extra cellular plasmid. This virus is harmless to man and therefore makes an excellent source of DNA. The DNA of the phage is double stranded and is in the linear form phage particle is 48.5kb pairs. At each end are short single stranded Cohesive ends of 5’projections of 12 nucleotides which are complementary in sequence 5′-GGG CGG CGA CCT-3′, 5′-AGG TCG CCG CCC-3′ are present. In recombination process the cohesive ends of Lambda DNA associate to form cos site. DNA portion of cos sites is rich in Guanine Cytosine (GC) bases.Then current work relies on the principle that the Thiol group has an affinity towards the gold particles. This property of affinity is used for immobilization of DNA on the Solid Surface.

Conclusion

From the methods used for immobilization it can be conferred that in the dry conditions the receding meniscus results in the aggregation of DNA along with the impurities and formation of Dendrite structures .When humid conditions are maintained more of the DNA is on the electrodes. Sometimes it appears in between the Microelectrode surface. The current work can also be extended to test the Electrical conductivity of λ-DNA using DNA covalently bonded to gold electrodes. If the results are positive this could be an important mile stone in the development of nano-devices.

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