What technique involves using an electric field to separate DNA in agarose?

The technique that involves using an electric field to separate DNA in agarose is gel electrophoresis. This method is widely used in molecular biology to analyze and separate macromolecules, particularly DNA, based on their size.

In gel electrophoresis, an agarose gel is prepared, which acts as a matrix for the DNA fragments. When an electric current is applied, the negatively charged DNA molecules migrate toward the positive electrode. Smaller fragments move through the pores of the agarose gel more easily and therefore travel further in the field, while larger fragments experience more resistance and move more slowly. This size-based separation allows researchers to analyze the composition of DNA samples, assess the results of PCR amplifications, and purify specific DNA fragments for further study.

The other options are distinct techniques or processes. Transcription refers to the process of synthesizing RNA from a DNA template, while standard operating procedures (SOPs) are documented guidelines for achieving consistent results in laboratory techniques and procedures. Activity assays are experimental setups designed to measure the functional activity of different biological molecules but do not specifically involve the separation of DNA through an electric field.