Coverage (genetics)

Coverage or depth in genetics refers to the number of times a given nucleotide has been read for sequencing in genetic mapping. While sequencing is highly accurate, the human genome has a vast number of nucleotides and so even a low error rate can produce a significant number of errors if the whole genome is only read once. Repeatedly reading the same sequence offers the opportunity to eliminate errors.

In 2011 paper for Genome Research, Ajay et al. arqued that ''that the current recommendation of ∼30× coverage is not adequate to produce genotype calls across a large fraction of the genome with acceptably low error rates."