Petrifilm Salmonella Express
RAPID DETECTION AND BIOCHEMICAL CONFIRMATION OF SALMONELLLA
Product Overview and Intended Use
The Neogen® Petrifilm® Salmonella Express (SALX) System provides rapid, reliable detection and biochemical confirmation of Salmonella species in enriched food and food process environmental samples. The system reduces testing time to under 48 hours while maintaining ISO 9001 certified manufacturing standards. Designed for trained laboratory professionals, this system delivers consistent, reproducible results for pathogen detection in compliance with international standards. Approvals: AOAC® Official Method of AnalysisSM (OMA) 2014.01 and AOAC® Performance Tested (PTM) Certificate #061301
System Components
- Neogen® Salmonella Enrichment Base — optimized nutrient formulation for Salmonella recovery.
- Neogen® Salmonella Enrichment Supplement — selective additive providing improved specificity.
- Neogen® Petrifilm® Salmonella Express Plate — chromogenic medium providing presumptive identification.
- Neogen® Petrifilm® Salmonella Express Confirmation Disk — facilitates biochemical confirmation of Salmonella colonies.
Principle of the Method
Samples are enriched in Neogen® Salmonella Enrichment Base supplemented with the Neogen® Salmonella Enrichment Supplement. After incubation at 41.5 ± 1.0°C for 18–24 hours, the sample is plated onto the Neogen® Petrifilm® Salmonella Express Plate. Presumptive positive colonies appear as red or brown with yellow zones and/or gas bubbles. Confirmation is performed using the Neogen® Petrifilm® Salmonella Express Confirmation Disk, resulting in blue to black colonies with blue precipitate.
Safety Information
⚠️ WARNING: For laboratory use only. Do not use for diagnostic purposes in humans or animals. Follow Good Laboratory Practices (GLP) including the use of appropriate personal protective equipment (lab coat, gloves, eye protection). Dispose of enriched materials and plates according to local biohazard regulations.
Storage and Disposal
- Store unopened Petrifilm® Plates and Confirmation Disks at 2–8°C, protected from light and moisture.
- Opened materials: store sealed at -20 to -10°C for up to 4 weeks.
- Enrichment Base and Supplement: store tightly sealed at 2–8°C.
- Dispose of all used materials as biohazard waste following local standards.
Overview of Preparation and Testing Procedure
- Prepare the enrichment medium by adding 50 mg (±2.5 mg) of Neogen® Salmonella Enrichment Supplement per liter of sterilized Neogen® Salmonella Enrichment Base at 20–42.5°C. Mix thoroughly.
- Add sample to prewarmed enrichment medium. Homogenize and incubate at 41.5°C for 18–24 hours.
- For high microbial load samples, transfer 0.1 mL into 10 mL Rappaport-Vassiliadis (R-V) R10 broth and incubate for 8–24 hours.
- Hydrate one SALX Plate with 2 mL ± 0.1 mL of sterile diluent. Allow gel formation for 1 hour at room temperature.
- Streak a 10 μL loop across the gel to isolate colonies. Incubate for 24 ± 2 hours at 41.5°C.
- Circle presumptive colonies and add the Confirmation Disk. Incubate 4–5 hours at 41.5°C.
- Interpret results.
Interpretation of Results
- Presumptive Positive: Red to brown colonies with yellow zones or gas bubbles.
- Confirmed Positive: Blue to dark blue/black colonies with blue precipitate after confirmation.
- Non-Salmonella: Red colonies without yellow zones or gas bubbles, or blue-green colonies without confirmation reaction.
Limitations and User Responsibility
The Neogen® Petrifilm® Salmonella Express System does not differentiate among Salmonella serotypes or certain lactose-positive strains. Users must validate the method with their specific matrices and ensure test results meet internal and regulatory quality requirements.
Resources
Ordering Details
Stock Code Description Pack Size
3MSEB500 Neogen Salmonella Enrich Base 500g
3MSESEUP001 Salmonella Plate Enrichment Supplement 10
3M6536 Petrifilm Salmonella Plates (SALX) 50
3M6537 Petrifilm Salmonella Plates (SALX) 200
3M6538 Petrifilm Salmonella Disks 5
3M6539 Petrifilm Salmonella Disks 25
