Final answer:
In Illumina's next-generation sequencing, nucleotides are identified using synthesis sequencing. The DNA sample is fragmented, modified with DNA adapters, and amplified by PCR. Each bead with a DNA fragment is put into a well with sequencing enzymes, and the detection of light flashes determines the order of nucleotides.
Step-by-step explanation:
In Illumina's next-generation sequencing, the nucleotides are identified by synthesis sequencing. In this process, the DNA sample is fragmented and modified with DNA adapters. Each fragment is immobilized on a bead and amplified by PCR, creating many copies of that DNA fragment on the bead. Each bead is then placed in a well with sequencing enzymes, and the four nucleotides are added one by one. When a nucleotide is incorporated, pyrophosphate is released, emitting a small flash of light that is recorded by a detector. This allows the order of nucleotides to be determined and the DNA sequence to be obtained.