Applications of bacterial transformation are :
1) to make multiple copies of DNA called DNA cloning.
2) to make large amounts of specific human , for example human insulin, which can be used to treat people with Type 1 diabetes.
3) to genetically modify a bacterium or other cell.
are commonly used as host cells for making copies of DNA in the lab because they are easy to grow in large numbers . Their cellular machinery naturally carries out and protein synthesis.