Which of the following techniques is based on the principle of antigen-antibody interaction?

$ELISA$ technique is based on the principles of antigen-antibody interaction. Can this technique be used in the molecular diagnosis of a genetic disorder,such as phenylketonuria?

In which bacteria was the gene for insulin cloned?

$ADA$ deficiency results in

The first clinical gene therapy was given in $1990$ to a $4$-year-old girl with an enzyme deficiency of:

Explain the molecular diagnosis methods for the diagnosis of diseases.