Question

Why was the sequencing technology of next-generation a breakthrough relative to classical gene-by-gene sequencing technology?

Answer 1

Next generation sequencing is also called high throughput sequencing or massive parallel sequencing. It is said that by Sanger's sequencing, the human genome can be sequenced fully in 2 years, but by next generation sequencing, this can be achieved in a single day.

In next generation sequencing, the DNA to be sequenced is first fragmented, sequencing adaptors are attached, then it is immobilised on a sequencing slide, clonal amplification of the DNA is done, which is then sequenced. Hence large amount of sequencing is done in a single assay.

Sequencing and detection are done simultaneously. Millions of sequencing reactions are done in parallel. A single region is sequenced multiple times. Hence the results are highly accurate.

It has several applications

1) In cancer studies to find out tumour subclones

2)To identify microbes rapidly

3)To study microbial diversity

4)To study gene expressions by RNA sequencing