Final answer:
To sequence DNA, multiple copies of DNA fragments are generated using techniques such as PCR and next-generation sequencing. These processes enable rapid, efficient sequencing of large quantities of DNA by amplifying small fragments and using computer algorithms to reconstruct the complete genomic sequence from overlapping segments.
Step-by-step explanation:
Generating Multiple Copies of DNA Fragments for Sequencing
To carry out sequencing, multiple copies of DNA fragments are generated through methods like polymerase chain reaction (PCR) and next-generation sequencing techniques. With PCR, a small segment of DNA can be amplified to produce millions of copies. This is essential for sequencing because a sufficient amount of DNA is needed to determine the nucleotide sequence accurately. Next-generation sequencing has further advanced the field by rapidly and simultaneously sequencing millions of fragments. Techniques like pyrosequencing and Illumina's technology involve fragmenting the DNA, adding adapters, and amplifying these fragments on beads before sequencing occurs, allowing for efficient and quick assembly of the entire genomic sequence.
In the case of shotgun sequencing, the DNA is randomly cut into numerous fragments, which are then individually sequenced. Computer algorithms analyze these sequences for overlapping regions to assemble them into a complete sequence, much like piecing together a jigsaw puzzle from randomly torn pieces of a photograph where only overlapping elements give a clue about the correct order of the pieces.