[bharatbuk]

DNA based diagnosis:
Most recent advances in diagnostics comes from the field of molecular biology.The cloning and manipulating of genetic material has led to the development of extremely sensitive diagnostic system.
The DNA probe is created by purifying the infectious agent of interest and isolating it's nucleic acid.Exact copy of DNA is made by cloning process.This copy bind to the original DNA of the pathogen whenever two come in contact.In order to accomplish this,DNA strand of both the pathogen must first be separated by heating.After separating,one of the strand of the probe can bind to it's complementary strand from the pathogen.By attaching non-radioactive reporter molecule,the hybrid DNA can be identified and measured.
Polymerase chain reaction is important application of this diagnosis.