Tag Archives: Melting Curve Analysis

Response surface methodology to design a selective enrichment broth for rapid detection of Salmonella spp. by SYBR Green Ι real-time PCR

Appl Microbiol Biotechnol. 2013 Mar 7. [Epub ahead of print]
Zhang Q, Chen T, Yang S, Wang X, Guo H.

Source

Zhejiang Province Key Lab for Food Safety, Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, Zhejiang, China, yanyan0014@sina.com.

Abstract

In order to meet dominant growth of Salmonella spp. in a composed system of five pathogens for accurate detection, designing an appropriate selective enrichment broth was clearly needed. First, we built a high-throughput assay procedure based on SYBR Green Ι real-time PCR, which possessed the necessary specificity for Salmonella spp., a good linear standard curve with typical R 2 value (0.9984) and high amplification efficiency (99.0 %). Further, for the larger target biomass in the mixed microflora, acarbose, LiCl and bile salt were selected to optimize their concentrations using response surface methodology (RSM). A central composite design was employed to collect the data and fit the response. A quadratic polynomial model was derived by computer simulation. Statistical analysis was carried out to explore the action and interaction of the variables on the response. In the end, a novel broth (Sal-5) was formulated to allow the efficient enrichment of Salmonella spp. and inhibit the growth of other tested strains. A detection platform was developed, including selective enrichment in Sal-5, DNA extraction by the boiling lysis method and real-time PCR test based on SYBR Green Ι. This work could extend the application of RSM and real-time PCR in the design of other selective enrichment media for common pathogens.

Excised radicle tips as a source of genomic DNA for PCR-based genotyping and melting curve analysis in cotton

J Biosci. 2013 Mar;38(1):167-72.
Rao PS, Kumar PS, Sonti RV.

Source

Centre for Cellular and Molecular Biology (CCMB), Uppal Road, Hyderabad 500 007, India.

Abstract

Genomic DNA isolation in cotton is complicated because of the presence of secondary metabolites that are inhibitory to PCR amplification. We report here that radicle tips, but not other parts of cotton seedlings, yield high-quality DNA that is readily amenable for PCR. The radicle-tip-excised seedlings retain viability because of the formation of adventitious roots. We demonstrate the utility of this method in distinguishing homozygotes from heterozygotes in a cotton breeding population and in hybrid seed purity testing.