Usage of Compact Dry SL is a simple and safe test procedure for detection of Salmonella in pre-enriched samples of foods or raw materials. The plates consist of a special 50 mm diameter petri dish containing a detection specific nutrient pad.
The ready-to-use, chromogenic Compact Dry plates are suitable for in-process controls as well as controls of finished products. With the Promedia ST-25 swab tests (Art. No. Z0302, available from R-Biopharm) Compact Dry plates may also be used for surface sampling and therefore applied for quantitative hygiene monitoring even at surfaces which are difficult to reach.
Using Compact Dry SL Salmonella can be detected from a specific sample pre-enrichment. The detection can be performed safe and easily according to three different criteria:
1. Color change of the medium from blue-purple to yellow, caused by the alkalization of the medium which is initiated by the Salmonella-specific enzyme lysine-decarboxylase
2. Appearance of black-green colonies due to degradation of the chromogenic substrate (green) which is contained in the medium combined with the Salmonella specific production of iron hydrogen sulfide (black)
3. The motility of Salmonella which is observed by colonies appearing not only at the origin of inoculation, but also at other areas of the nutrient pad
|100 nutrient plates or 40 nutrient plates, respectively – – where four plates are packed in one aluminum bag
|Pre-enrichment procedure according to common Salmonella regulations (normally two step selective pre-enrichment)
100 µl of pre-enrichment will be applied to the nutrient pad while 1 ml sterile water has to be added afterwards
|20 – 24 hours at 41 – 43 °C
|depends on the kind of application or the degree of dilution of samples
|12 months at 1 – 30 °C (from date of manufacture)