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Pathogen Detection with GeneGen®Test Systems
Easy-to-apply biomolecular detection of pathogenic microorganisms in foodstuffs! Our GeneGen®kits employ a novel DNA amplification and hybridization protocol using multiplex PCR followed by a shortened hybridization reaction (the GeneGen®technology) for the detection of pathogenic microorganisms from liquid cultures (e. g. enrichment cultures) or agar plates (single colonies).
User-friendly, fast, reliable!
- No tedious pipetting!
PCR tubes contain freeze-dried, ready-to-use master mix – only the extracted sample has to be added. Laborious pipetting of PCR reagents, pipetting errors and the danger of contamination are obviated. - Convenient and time-saving!
The special assay format enables a strong reduction of the standard protocol for DNA hybridizations and processing at ambient temperatures (20-30 ºC), thus providing a considerable saving of time and dispensing with the usual cumbersome incubation of hybridization reactions in water baths or hybridization ovens. To carry out hybridization, only an orbital shaker or a rocking platform is needed. - Reliable and sensitive!
1-10 colony-forming units / 25g of foodstuff are detectable, in many cases after the pre-enrichment step, within 24 hours.
Internal positive control for monitoring of reaction is integrated!
The following test kits are available:
- GeneGen®EHEC Detection Kit
Detection and characterization of enterohemorrhagic Escherichia coli strains within 24 hours! - GeneGen®Salmonella Detection Kit
Detection of salmonellae within 24 hours! - GeneGen®Listeria Detection Kit
Detection of genus Listeria and Listeria monocytogenes within 3 working days! - GeneGen®Major Food Pathogens Detection Kit
Detection of salmonellae, EHEC, Listeria monocytogenes und Campylobacter in a single amplification reaction!
Considering as example:
GeneGen® EHEC Detection Kit
DNA detection system based on a patented multiplex-PCR technique combined with a hybridisation step for the detection and characterization of enterohemorrhagic Escherichia coli strains from liquid cultures (e.g. enrichments) and from agar plates (single colonies).
Assay principle
The GeneGen® EHEC Detection Kit is intended for the detection and partial characterization of EHEC strains, based on molecular biology methods. Four typical genes that can be present in EHEC, the genes for Shiga-like toxins 1 and 2, an O157-specific gene, the intimin gene (eaeA), and an internal positive control are amplified in a single reaction (multiplex-PCR) and detected afterwards by sandwich hybridization and color development. The special assay format enables a strong reduction of the standard protocol for DNA hybridizations and processing at ambient temperature (20-30 ºC), thus providing a considerable saving of time and avoiding the usual cumbersome incubation of hybridizations in water baths or hybridization ovens.
Working steps:
| step | duration |  |
| cultivation on plates or in liquidculture (e.g. enrichment culture from minced meat) |
overnight (16-18 h) |
|
| DNA extraction |
< 1 h | |
| PCR |
approx. 2,5 h | |
| hybridization |
approx. 1 h | |
| colorimetric detection | max. 2 h | |
 |
|
In most cases, detection is possible within 24 hours without much effort and little hands-on time, the actual assay time (without cultivation) not exceeding 6-7 hours.
Beside O157, other EHEC serotypes (STEC = Shiga toxin producing Escherichia coli), enteropathogenic E. coli strains (EPEC) and other Shiga toxin producing bacterial genera, like Shigella dysenteriae, can be detected, depending on the gene(s) that is (are) present.
 |
Typical results GeneGen EHEC |
| Detected genes (from left to right): | |
| Shiga-like toxin 1 (a) | |
| Shiga-like toxin 2 (b) | |
| O157-specific gene (c) | |
| eaeA (d) | |
| internal positive control (e) | |
| hybridization negative control (f) | |
Quick reference procedure
- Perform enrichment or plate culture for 16-18 hours.
- For single colonies: Resuspend a single colony in 100µl of molecular biology grade water and proceed with step 6. For liquid cultures: Remove 100µl of culture and transfer to a tube.
- Pellet bacteria by centrifugation.
- Discard supernatant, wash bacterial pellet with 100µl of molecular biology grade water and centrifuge as above.
- Discard supernatant and resuspend bacteria in 100µl of molecular biology grade water.
- Heat sample to 95-100°C, let cool down and centrifuge.
- Apply 25µl of supernatant in PCR.
- Prepare test strips, denature PCR products and prepare hybridization mix.
- Hybridize for 30 min.
- Wash 2x10 min and prepare developing solution.
- Equilibrate strips for 1 min.
- Up to 2 h color development.
Download GeneGen Catalogue
in *pdf Format (Acrobat Reader)
