Doehler Launches Optimized Culture Media for PCR Detection

22 Mar 2016 --- Fast approval of beer samples for breweries is extremely important in beer production. Molecular-biological detection using PCR (polymerase chain reaction) has today developed into the fastest and most reliable method for detecting and identifying beverage spoiling microorganisms. For this purpose, Doehler offers its ready-to-use NBB-PCR Broth, which was developed especially for this detection method.

The optimized composition of the raw materials in the medium promotes fast growth in the beer spoiling microorganisms and fast detection. NBB-PCR Broth offers an advantage that no other product can: a special production process makes NBB-PCR Broth free from DNA spoiling microorganisms and PCR inhibitors of any kind.

As a result, false positive and false negative results, both of which can have expensive consequences for breweries, are ruled out. The medium can be combined with all PCR and real-time PCR detection systems available on the market, making it suitable for universal use. It allows the analysis of all samples taken in breweries, from yeast to yeast-turbid beer.

The NBB-PCR Broth was developed for fast and reliable detection of beverage spoiling microorganisms such as Lactobacillus, Pediococcus, Pectinatus and Megasphaera, and for all samples arising in breweries. Some culture media consist of raw materials that are already contaminated with DNA from other microorganisms. “This would lead to a false positive PCR result, forcing the brewery to spend time and money retesting perfectly good beer or, in the worst case scenario, throwing it away. We can rule this out 100% with the new NBB-PCR Broth,” says Dr Sabine Müller, Head of Product Management & Sales, DMD Culture Media at Doehler.

Thanks to a production process specially tailored to this aspect, Doehler is the only producer who can guarantee that NBB-PCR Broth contains no DNA from beverage spoiling microorganisms. The medium also contains no inhibitors at all that influence the PCR or real-time PCR. This enables enrichment and detection within just 48 to 72 hours, even of slow-growing microorganisms like Lactobacillus lindneri or Pediococcus damnosus, for example.

NBB-PCR Broth was validated in an extensive study by Dr.-Ing. Mathias Hutzler from the Microbiology and Yeast Center department of the Research Center Weihenstephan for Brewing and Food Quality at Technische Universität München. The investigation included comparing the culture medium NBB-PCR with other culture media and its use in combination with various commercially-available PCR detection systems and a range of sample matrices. Comprehensive publication of the results is planned.

The balanced ratio of growth substances and inhibitors in NBB-PCR ensures optimum selectivity, allowing strictly anaerobic beer spoiling microorganisms such as Pectinatus und Megasphaera to be detected in just 48 to 72 hours. Doehler ensures that NBB-PCR Broth offers consistent quality at the highest level using a comprehensive quality management system and internal and external examinations, from the raw material to the end product.

The medium can be used universally for the enrichment of and subsequent PCR or real-time PCR detection in yeast samples, yeast-turbid beers, filtered beers, water and rinsing water, samples from airborne bacteria collection and swab samples for hygiene monitoring. NBB-PCR Broth is suitable as pre-enrichment for all PCR or real-time PCR systems, regardless of the detection system used. It is ready to use right away, thus eliminating the need for any preparation. There is no need for the usual cumbersome and time-consuming weighing, dissolving, pH adjustment and autoclaving – another feature that makes NBB-PCR Broth stand out from other media.

NBB-PCR Broth is perfect for combining with the new DMD Screen & Ident Kits from Doehler. The new kits offer fast and absolutely reliable results and are so easy to use that no expert knowledge of microbiology is needed. Once the beer samples have been enriched with NBB-PCR Broth, the DMD Screen & Ident Kits can be used directly to detect beer spoiling microorganisms. The kits combine optimized PCR detection with detection that uses a test strip and is easy to analyse visually.

The company has also launched the new DMD Screen & Ident Kits, which offer a real innovation in microbiological quality control for breweries. Until now, both cultural analysis methods and those based on real-time PCR were very cumbersome, cost-intensive and only possible with trained staff. With its DMD Screen & Ident Kits, Doehler provides breweries with a simple, fast and cost-effective method of detecting beer spoiling microorganisms, which allows microorganisms in an enriched beer sample to be detected and identified in just an hour. The method combines molecular-biological PCR detection with simple visual analysis on a test strip. This combination reduces the time needed for cultural detection – usually five days or more – to just two to three days including pre-enrichment. Its ease of use makes the system especially attractive; no specific knowledge of molecular biology is required for the test.

The innovative DMD Screen & Ident Kits combine the high sensitivity of the PCR (polymerase chain reaction) method with the easy application of lateral flow detection. The positive or negative result in each case is easy to read from colored lines on a test strip, with no need for expert knowledge or expensive equipment. First, the genetic material of any microorganisms present is released from an enriched sample that is simply heated with a prepared reaction mix in a PCR thermal cycler. A small quantity is applied to a test strip after just a 50-minute PCR program. Once dipped in an assay buffer, this test strip can be analyzed after a further five minutes.

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