<prompt> Oncogenes can be best studied byTransfectionTransductionTransformationConjugation  <response>: Transfection is the process of deliberately introducing naked or purified nucleic acidsinto eukaryotic cells. It may also refer to other methods and cell types, although other terms are often preferred: transformation is typically used to describe non-viral DNA transfer in bacteriaand non-animal eukaryotic cells, including plant cells. In animal cells, transfection is the preferred term as transformation is also used to refer to progression to a cancerous state carcinogenesis in these cells. Transduction is often used to describe virus-mediated gene transfer into eukaryotic cells. Ref satyanarayana 4e 