Figure 3
From: Computational tradeoffs in multiplex PCR assay design for SNP genotyping
Multiplex PCR performance tradeoffs. A closer examination of the Fixed Assignment Best-Fit algorithm reveals tradeoffs between the available number of SNPs, N, the target multiplexing level, M, and full-tube coverage. The dip at N = 1000, M = 30 is an artifact of the algorithm which strictly limits the number of tubes to 
= 34 tubes. Since M does not divide N evenly, the algorithm ends up partially filling the excess tube rather than working harder to fill the remaining 33 tubes to full 30-plex capacity.