PCR for confirming the presence of transferred gene

When a gene is transferred with a vector to cultured cells or organisms, primers can be designed to conduct PCR for amplification of the gene sequence so transferred. This technique allows confirmation of.. the transfer and maintenance of the gene of interest. In gene therapy experiments, the transfer and presence of it marker gene for neomycin resistance (NeoR) could be detected in the blood of patients, even after 60 days, although the frequency of marked lymphocytes gradually decreased necessitating a second' transfusion of such marked cells.

Similarly, ADA (adenosine deaminase deficiency) gene was transferred. for therapeutic purposes and PCR was used to detect the presence of this gene upto 6.5 months, so that the patient (4 year old girl) was then placed on a programme of maintenance infusions at 3-5 months intervals. Thus PCR proves to be of immerse help in monitoring a gene in genetic engineering or gene therapy experiments