Biology / Unit 7 Bio 1569 short lesson, about 20 seconds
Sanger Chain-Termination Sequencing
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The idea
Sanger chain-termination sequencing, developed by Fred Sanger in the 1970s, reads DNA using fluorescently labeled dideoxynucleotides that halt replication wherever incorporated.
In practice
A dideoxynucleotide lacks the hydroxyl group needed to attach the next nucleotide, so wherever one is added, that fragment's synthesis stops.
Where people slip
Each dideoxynucleotide's fluorescent label, not its position alone, lets the resulting fragment ladder be read back into a sequence.
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