Which statement best contrasts Sanger sequencing with next-generation sequencing?

Which statement best contrasts Sanger sequencing with next-generation sequencing?

• A. Sanger sequencing is highly accurate (>99.9%) but low throughput; NGS has higher throughput with shorter reads and generally higher error rates depending on platform.
• B. Sanger sequencing is faster but less accurate; NGS is slower but more accurate.
• C. NGS yields longer reads with lower error rates.
• D. Sanger sequencing can sequence thousands of reads in a single run.

Answer: (A)

The key idea is how these methods trade off accuracy, read length, and how much data you can generate at once. Sanger sequencing gives very high per-read accuracy, with reads that are fairly long for a single, capillary-based run. But you can produce only a modest number of reads per run, so it’s low throughput. Next-generation sequencing runs many DNA fragments in parallel, delivering millions of reads in one run, but the reads are much shorter (on the typical Illumina-style platforms) and the per-read error rate is higher than Sanger’s. Of course, with deep coverage, the overall sequence can be read very accurately, but the per-base error profile is still higher for many NGS technologies. Therefore, the best contrast is that Sanger is highly accurate but low throughput, while NGS provides high throughput with shorter reads and generally higher error rates depending on the platform. The other statements misstate these trade-offs: Sanger isn’t faster and isn’t often described as having higher throughput; NGS short reads don’t typically boast longer reads with lower error rates in standard workflows; and Sanger cannot sequence thousands of reads in a single run.

The key idea is how these methods trade off accuracy, read length, and how much data you can generate at once. Sanger sequencing gives very high per-read accuracy, with reads that are fairly long for a single, capillary-based run. But you can produce only a modest number of reads per run, so it’s low throughput. Next-generation sequencing runs many DNA fragments in parallel, delivering millions of reads in one run, but the reads are much shorter (on the typical Illumina-style platforms) and the per-read error rate is higher than Sanger’s. Of course, with deep coverage, the overall sequence can be read very accurately, but the per-base error profile is still higher for many NGS technologies. Therefore, the best contrast is that Sanger is highly accurate but low throughput, while NGS provides high throughput with shorter reads and generally higher error rates depending on the platform. The other statements misstate these trade-offs: Sanger isn’t faster and isn’t often described as having higher throughput; NGS short reads don’t typically boast longer reads with lower error rates in standard workflows; and Sanger cannot sequence thousands of reads in a single run.