Optimal library depth to minimize total cost, assuming that the ratio of the cost of obtaining the complete sequence of a BAC to the cost of sequencing both ends of a BAC is ρ = 1000:1. The top curve (marked d*) shows the optimal depth when using a single library. The two lower curves show the optimal depths d andd′ when using two library B and B′, as described in the text. The optimal depths depend on the mean initial ocean size θ. The depth d′ of the small insert library was constrained to be at least 5, to ensure that the existence of a properly situated, small-insert clone at the end of the vast majority of islands, consistent with the assumption ACO, described in the text.
