Two-dimensional gel electrophoresis of replication intermediates is used to study what?

• A. Identification of replication intermediates and fork structures.
• B. Protein expression quantification.
• C. Global genome sequencing.
• D. Chromosome staining to detect telomere length.

Answer: (A)

Two-dimensional gel electrophoresis of replication intermediates is designed to separate DNA not only by size but also by shape, so you can reveal the distinct forms that appear during replication. Replication intermediates include bubble structures that form at origins of replication and Y-shaped fork structures as replication forks move along the template. On a 2D gel, these forms produce characteristic patterns—bubble forms create a bubble arc and forks create Y-shaped arcs—allowing you to identify where replication starts, how far forks progress, and whether forks pause or stall. This makes the technique ideal for identifying replication intermediates and mapping fork structures.

It isn’t used for quantifying protein levels, sequencing entire genomes, or staining chromosomes to measure telomere length, which are tasks better suited to proteomics methods, sequencing technologies, or telomere-assessment techniques, respectively.