Pre-supplemented Fraser Broth – selective broths for secondary enrichment of Listeria in the analysis of food products according ISO11290
- Format: 500 g
- Code: TN1035
- Technology: Culture media and ISO confirmation tests
- Application: Food/Water microbiology
- Tag/Filter: Listeria
Fraser broths are used for primary (Half Fraser) and secondary (Fraser) enrichment in the detection of Listeria spp. in food products according to ISO11290. The combined action of lithium chloride, acriflavin and nalidixic acid, present in these broths inhibits the concomitant flora ensuring the biological space for the growth of Listeria. These two broths are lightly buffered to slow down acidification (acidifying flora), which inhibits the growth of Listeria. After enrichment (primary or secondary), the presence of Listeria is evidenced by a change in the color of the broth that becomes yellow to dark brown (due to the hydrolysis of the esculine present as an ingredient). However, this change of colour is not systematic and according to ISO11290 it is also essential to carry out insulation on a selective soil (ALOA, PALCAM and/or Oxford). SIFIN Fraser broths are available in the convenient dehydrated powder format already supplemented or as a dehydrated base powder from supplemental.
- Format: 500 g
- Code: TN1035
- Technology: Culture media and ISO confirmation tests
- Application: Food/Water microbiology
- Tag/Filter: Listeria
