What is the composition of the QIAGEN Multiplex PCR Buffer?
FAQ ID -289

The exact composition of the QIAGEN Multiplex PCR Buffer supplied in the QIAGEN Multiplex PCR Kit is proprietary. The buffer contains a specially developed balanced combination of salts and additives to ensure comparable efficiencies for annealing and extension of all primers in the reaction, thereby facilitating the amplification of multiple PCR products in a single tube.

The QIAnews article 'Highly efficient multiplex PCR using novel reaction chemistry' provides additional details and describes the advantages of this buffer in contrast to conventional PCR reagents.