What distinguishes dye-terminator Sanger Sequencing from the traditional method?

Dye-terminator Sanger Sequencing is distinguished from traditional Sanger sequencing primarily due to its use of labeled dideoxynucleotides (ddNTPs) that terminate strand elongation during the DNA synthesis process. In this modern approach, each ddNTP is labeled with a different fluorescent dye, which allows for the simultaneous identification of all four bases (adenine, thymidine, cytosine, and guanine) in a single reaction. As the DNA polymerase incorporates these labeled ddNTPs, when a ddNTP is added to the growing DNA strand, further elongation is stopped, producing fragments of varying lengths corresponding to the DNA sequence.

The incorporation of fluorescent labels facilitates automated detection and analysis through capillary electrophoresis, where the differentially colored fragments can be separated and detected, significantly enhancing the efficiency and accuracy of sequencing compared to older methods that often used radioactively labeled nucleotides requiring more complex and labor-intensive processes.

The other options present methods or components that do not specifically differentiate dye-terminator sequencing from traditional Sanger Sequencing. For instance, while radioactive labels were commonly used in older sequencing techniques, the dye-terminator method specifically utilizes fluorescent labels for detection. Although PCR amplification is