If a scientist wants to analyze the size of DNA fragments, which method would they likely use?

Electrophoresis is the most suitable method for analyzing the size of DNA fragments due to its ability to separate charged molecules, such as nucleic acids, based on their size. In this technique, an electric field is applied across a gel medium, which causes the DNA fragments to migrate through the gel. Smaller fragments move faster and travel further than larger ones, allowing scientists to determine the size of the various DNA pieces by comparing their distances traveled to a DNA ladder or standard.

The specificity of electrophoresis for DNA size analysis makes it widely used in genetic research, forensic science, and molecular biology. The method is effective for resolving and visualizing fragments after amplification or restriction enzyme digestion, thus providing clear insights into the size differences among the DNA fragments being tested.

Other methods like gel filtration, mass spectrometry, and chromatography serve different purposes in molecular analysis and separation but lack the direct applicability and specificity for size determination of DNA fragments that electrophoresis provides.