What does transformation refer to in genetic engineering?

Transformation in the context of genetic engineering refers specifically to the process by which new genetic material is introduced into an organism, particularly through the uptake of plasmids. This process allows for the incorporation of foreign DNA into a host organism's genome, enabling traits such as resistance to diseases, production of proteins, or other desirable characteristics.

Understanding transformation is critical because it is one of the foundational techniques used in molecular biology for cloning and gene expression. Typically, bacteria, especially strains like E. coli, can be transformed with plasmids that carry the desired genes. Once transformed, these bacteria can replicate the plasmids as they divide, leading to the amplification of the new genetic material.

The other options describe different techniques or processes that do not accurately capture the concept of transformation in genetic engineering. Creating pure cultures involves isolating a single species of microorganism, sterilizing DNA samples pertains to decontamination methods, and extracting DNA focuses on isolating genetic material, none of which relate to the specific incorporation of new genes into an organism's genome via plasmid uptake.