Explain molecular diagnosis giving one example.

Explanation

Early detection of a disease, using conventional methods like urine, serum analysis is not possible. So recombinant DNA technology, PCR, ELISA, probes serve the purpose of early diagnosis. Very low count of pathogen like virus bacteria (when symptoms of disease are not there) can be detected by multiplication of their nucleic acid by PCR. It is not now usually used to detect HIV in suspected AIDS patient. Similarly probes are also used.
Probes. They are small (15-30 bases long) single stranded nucleotide (DNA/RNA sequences used to detect the presence of compleinentary sequences in nucleic acid samples. They are prepared in many ways and are either radioactively or non-radioactively labelled.
Use of probes considered better than conventional diagnostic tools for disease diagnosis. Probes are better than conventional diagnostic tools because :
1. They are highly specific, relatively rapid and much simpler.
2. They are extremely powerful especially when combined with PCR, even a single molecule in the test sample can be detected.
3. Since culture of microbe is not required, risk of accidental infection to laboratory personnel is eliminated.