Molecular Beacons: A Real-Time Polymerase Chain Reaction Assay for Detecting Salmonella

Reduced PCR Sensitivity Due to Impaired DNA Recovery with the MagNA Pure LC Total Nucleic Acid Isolation Kit

“…To comply with the demands for sensitivity and reliability, highly qualitative methods for extraction, amplification, and detection of nucleic acids (NA) are required. Most amplification-detection systems today, like PCR-hybridization and real-time PCR, have the analytical power to detect and identify a single target molecule (5,7,8,9,22). When combined with the extraction procedure developed by Boom et al (Si extraction) (3), acknowledged for its potency in removing inhibitors from clinical samples and widely used for the purification of NA from a variety of clinical samples (2,6,24), optimal clinical sensitivity and reliability are achieved.…”

“…For instance, HCV RNA recovery seems to be less efficient with M extraction and analysis by the (COBAS) AMPLICOR HCV 2.0 test (10,11,14) compared to other manual (Roche) and automated (NucliSens) extraction procedures (1,19). Furthermore, for enterovirus RNA, Knepp et al (16) [7][8][9][10]2004) have shown that M extraction was 0.5 to 1.0 log 10 less sensitive compared to the NucliSens miniMAG platform.…”

Rapid label-free DNA analysis in picoliter microfluidic droplets using FRET probes

“…The distinctive biomolecular recognition and signal transduction capabilities of molecular beacons (MB) (Tyagi and Kramer 1996) have increasingly been applied to many medical diagnosis applications (Chen and Kwok 1997;Piatek et al 1998) and biological assays, including genotyping for SNP (Kwok 2001;Syvanen 2001), multiplex genetic analysis (Marras et al 1999;Vet et al 1999), quantitative PCR (Vogelstein and Kinzler 1999;Chen et al 2000), enzymatic reaction of proteins (Fang et al 2000;Tung et al 2000), and detection of mRNA in living cells (Sokol et al 1998;Tsuji et al 2000;Fang et al 2002). MB is a class of fluorescence resonance energy transfer (FRET) molecules that are synthesized in a hairpin structure with stem and loop portions.…”

Detection of Salmonella spp. Presence in Food

“…Samples for determination are taken from preenrichment cultures on buffered peptone water after 18 h incubation at 37°C, so the total time from the collection of a sample to the final results does not exceed 24 hours. Chen et al (2000) evaluated the TaqMan system for the detection of Salmonella that utilizes primers and probes developed from a novel target sequence (invA). The detection limit was below 3 CFU/25 g or 25 ml when raw milk, ground beef and ground pork inoculated with Salmonella were pre-enriched overnight.…”