1. What is the depth of sequencing?

When the depth of sequencing is 6 x, the coverage of the target region can reach 90%. When the depth is 20 x, the coverage of the exon region of reads is nearly saturated. At this time, further improving the sequencing depth has little contribution to the coverage, but it can increase the accuracy of SNPs detection and detect the potential rare lesions. So we can choose the appropriate sequencing depth according to the goal and funding of the experiment.
2. Can we sequence only a specific region of the genome?
The probe of the region of interest can be made, the DNA of the target region can be enriched and then sequenced by the new generation sequencing technology platform.
3. What are the advantages and disadvantages of exon sequencing compared with whole genome sequencing?
Compared with the whole genome sequencing, exon sequencing has the advantages of deeper sequencing coverage, higher data accuracy and lower cost. Combined with a large number of exon data provided by public database, sequencing data can better explain the results of the study. The disadvantage of this method is that it can only obtain the variation information of the inner or boundary of exon region, and can not detect the large structural variation in genome.