Quantitative multiplex real-time PCR assay for shrimp allergen: comparison of commercial master mixes and PCR platforms in rapid cycling.

Real-time PCR has been used widely in numerous fields. In food safety, it has been applied to detection of microbes and other contaminants, including food allergens. Interest in rapid (fast) cycling real-time PCR has grown because it yields results in less time than does conventional cycling. However, fast cycling can adversely affect assay performance. Here we report on tests of commercial master mixes specifically designed for fast real-time PCR using a shrimp allergen assay we previously developed and validated. The objective of this work was to determine whether specialized commercial master mixes lead to improved assay performance in rapid cycling. Real-time PCR assays were carried out using four different master mixes and two different rapid cycling protocols. Results indicated that specialized master mixes did yield quality results. In many cases, linear ranges spanned up to 7 orders of magnitude, R(2) values were at least 0.95, and reaction efficiencies were within or near the optimal range of 90 to 110%. In the faster of the two rapid cycling protocols tested, assay performance and PCR amplification were markedly better for the shorter PCR product. In conclusion, specialized commercial master mixes were effective as part of rapid cycling protocols, but conventional cycling as used in our previous work is more reliable for the shrimp assay tested.