Large scale multiplex PCR with 800 primer pairs. Gel electrophoresis of PCR products obtained with high complexity 800-primer pair mix (Additional file 1) with a final concentration of 0.02 μM for each individual primer pair and using Taq polymerase (standard LSplex) (A) or using vent exo-polymerase (B and C). Efficiency of LSplex using primer mix with different individual primer concentrations (B). Optimized LSplex amplification of various DNA templates from Gram-negative, Gram-positive bacteria and Candida albicans (C). 100 ng genomic DNA from each indicated species served as template.