Objective: We examined several critical parameters that must be optimized when converting between the ABI Prism 7700 real-time PCR platform and the Cepheid SmartCycler((R)) II while using the same primer and probe sequences. Design and methods: A lyophilized master mix, MgCl2 concentration, PCR cycling conditions, and ramp times were evaluated. Results: Optimization of each parameter, including use of the OmniMix(TM) HS-lyophilized beads, 6 mM MgCl2 concentration, changes in PCR cycling parameters, and increased ramp time were necessary to convert this real time PCR assay to a new platform. Conclusion: We conclude that careful consideration of several analytical parameters can result in a smooth transition of assays between real time PCR platforms. (C) 2004 The Canadian Society of Clinical Chemists. All rights reserved.