A latex agglutination presumptive test for the presence of Listeria spp to confirm colonies on agar plate media. Microgen Listeria latex may be used in conjunction with biochemical tests (Microgen Listeria-ID) for further species identification.
Benefits
- Results in 2 minutes
- Cost effective
- High sensitivity
- High specificity
- Accurate & reliable results
- User friendly procedure
Detects the Listeria genus, including these species:
- Listeria monocytogenes
- Listeria innocua
- Listeria welshimeri
- Listeria ivanovii
- Listeria seeligeri
- Listeria grayi
Included in the kit:
- 2.5mls Test latex
- 0.5ml Positive control
- 5mls Isotonic Saline
- disposable reaction cards
- disposable mixing sticks
Method from plates
- Place 1 drop of saline on to a well of the reaction card
- Remove a typical looking colony from the plate using a loop and emulsify in the drop of saline
- Rock the slide gently for 2mins to check for auto agglutination
- Add 1 drop of test latex to the suspension, mix using a mixing stick
- Rock the slide for up to 2 minutes and examine for agglutination
Interpretation
- Agglutination within 2 minutes is indicative of the presence of Listeria spp in the sample
- Absence of agglutination indicates that Listeria spp are not present in the sample
Latex Agglutination Principle
- Polyvalent antisera raised against the 4 Listeria flagella antigens is used to coat latex particles.
- When mixed with a suspension of Listeria containing these antigens, the latex particles rapidly agglutinate forming visible clumps
Latex technology:
- Producer strains carrying specific antigens are cultured at optimal temperature for flagella production
- isolates sub cultured on to Jameson plates to select most motile organisms
- strains cultivated in broth
- Supernatant discarded and cell deposit treated to harvest flagella
- flagella immunogen used to generate antisera
- antisera titres checked and blended
- blended antisera purified and then coated on latex particles
Listeria spp possess 4 major flagellar antigen types designated A, B, C and E. AllListeria spp possess one or more of A, B, or C butL. grayi only possess E. Antiserum used to coat the latex particles must contain all 4 flagella antigens in order to detect all 6 Listeria spp.
| Technical Information for Listeria Latex Agglutination Kit | |
| Storage: | Store at 2-8°C |
| Shelf Life: | 1 year |
| Detects the Listeria genus, including these species:
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