Quantitative PCR is an increasingly valuable tool in molecular diagnostics laboratories. However, there are many sources of variation in quantitative PCR and many challenges to development of quality control measures to monitor and/or mitigate these sources of variation. We have addressed these problems by developing a standardized mixture of internal standard competitive templates (SMISCT). For either PCR or RT-PCR, an aliquot of the SMISCT is included in each PCR reaction. This controls for a) variation in loading of cDNA into the PCR reaction b) cycle-to-cycle variation in amplification efficiency during PCR, c) sample to sample variation in presence of inhibitors, d) well-to-well variation in thermocycler amplification efficiency, and e) reaction-to-reaction variation in quality and/or quantity of PCR reagents. We have established a Standardized Expression Measurement (SEM) Center that offers high-throughput, standardized measurement of many genes simultaneously. Because gene expression is measured through comparison to a SMISCT, all gene expression data from all laboratories may be compared in an ever-expanding standardized expression database. This database serves as a virtually continuous multiplex experiment with the potential for nearly infinite accumulation of samples and genes measured. Importantly, this database enables identification of normal and pathological conditions. SMISCT for nearly 600 human genes have been developed and thousands more are in production. In addition, SMISCT for quantitative measurement of species-specific genes for most human microbial pathogens is in development. In summary, the SEM Center in conjunction with Gene Express is providing standards necessary to implement and monitor quality control required by regulatory agencies.

J.C.W and E.L.C. have significant interest in Gene Express, Inc. T.W.O., E.H., E.L, and B.J.Z. are with Gene Express, Inc.