PALCAM Listeria Selective Broth Base
Secondary Selective Enrichment Medium for Listeria

PALCAM Listeria Selective Broth Base (AS-1316)

$45.00 AUD

AuSaMicS Life Science • Listeria Selective Enrichment Media

PALCAM Listeria Selective Broth Base

Secondary Selective Enrichment Medium for Listeria

Highly selective enrichment broth designed for recovery of Listeria spp. from heavily contaminated samples. Based on the same selective principle as PALCAM Agar, this broth is used as an alternative or secondary enrichment step where stronger suppression of background flora is required in food, environmental, and hygiene monitoring workflows.

AS-1316 🧪 Selective Enrichment Broth ✓ Listeria Workflow Ready 🔬 PALCAM Selective System

Use: Secondary selective enrichment Readout: Dark brown to black broth Follow-up: Subculture to PALCAM, Oxford, or ALOA

Listeria Media Specialist

Strong Selectivity - Suppresses heavy competing flora

Esculin Reaction - Blackening supports presumptive detection

Secondary Enrichment Ready - Ideal after Half-Fraser or pre-enrichment

Food & Environmental Focus - Meat, fish, vegetables, surfaces

High-Throughput Utility - Useful in routine testing labs

High-Selectivity Listeria Enrichment

Designed for difficult, high-background samples

🧪 Complete Formulation & Selectivity Profile

📋 Complete Base Composition (per Liter)

Ingredient	Concentration	Primary Function	Contribution
Peptone Base	23.0 g	Nutrient support	Supports recovery of Listeria during selective enrichment
Starch	1.0 g	Protective / nutritional component	Helps reduce inhibitory stress and supports recovery
Sodium Chloride	5.0 g	Osmotic balance	Helps maintain suitable ionic conditions
Mannitol	10.0 g	Fermentable carbohydrate	Part of the selective differential concept
Esculin	0.8 g	Differential substrate	Hydrolysis contributes to blackening reaction
Ferric Ammonium Citrate	0.5 g	Indicator component	Forms dark complex after esculin hydrolysis
Glucose	0.5 g	Supplementary energy source	Supports early growth during enrichment
Lithium Chloride	15.0 g	Selective agent	Suppresses many competing organisms
Phenol Red	0.08 g	pH indicator	Supports colour-based differentiation logic

Final pH: 7.2 ± 0.2 at 25°C

📋 Selective Supplement (added after sterilization)

Supplement	Amount / L	Role
Polymyxin B	10 mg	Selective inhibition of competing flora
Acriflavine HCl	5 mg	Selective suppression of background organisms
Ceftazidime	20 mg	Additional selective activity against competing bacteria

⚗️ Functional Design

High Selectivity
PALCAM inhibitor system strongly suppresses heavy background flora

Esculin Blackening
Listeria growth is associated with dark brown to black broth reaction

Workflow Compatibility
Fits secondary enrichment schemes after pre-enrichment or Half-Fraser

Why PALCAM Broth? Useful when extra selectivity is needed against meat, fish, vegetables, or environmental background flora before subculture to selective agar.

Complete Listeria Enrichment & Isolation Media Portfolio

Medium	Type	Selectivity	Best Application	Typical Step	Key Advantage
PALCAM Listeria Selective Broth Base	Selective enrichment broth	High	Secondary enrichment of difficult samples	After pre-enrichment / Half-Fraser	Strong suppression of competing flora
Half Fraser Broth	Primary selective enrichment	Moderate	Initial recovery of stressed Listeria	First enrichment step	Better recovery of injured cells
Fraser Broth	Selective enrichment broth	High	Secondary enrichment in ISO workflows	Second enrichment step	Widely standardized in ISO methods
PALCAM Listeria Selective Agar	Selective differential agar	High	Isolation after enrichment	Plating step	PALCAM colony differentiation system
ALOA Agar	Chromogenic selective agar	High	Targeted Listeria isolation and differentiation	Plating / confirmation support	Chromogenic interpretation benefits

Strategic Medium Selection for Listeria Recovery

✅ PALCAM Broth Advantages

✓ High Selectivity: Useful for heavily contaminated samples
✓ Compatible with PALCAM Workflow: Shares the same selective logic as PALCAM Agar
✓ Visible Presumptive Readout: Darkening supports early detection
✓ Useful in High-Throughput Labs: Efficient for difficult matrices
✓ Strong Background Suppression: Helpful against enterococci, staphylococci, Bacillus, and Gram-negatives

⚠️ Method Considerations

▲ High Selectivity Can Reduce Recovery: Injured cells may require gentler primary enrichment first
▲ Supplement Required: Selective agents must be added after sterilization
▲ Not Universally Mandatory: Often used as an alternative or national-method enrichment step
▲ Subculture Still Needed: Positive broths should be plated for isolation and confirmation

🎯 Best-Fit Applications

◆ Meat & Fish Testing: Heavy background flora suppression
◆ Vegetable & Produce Microbiology: Secondary selective enrichment
◆ Environmental Monitoring: Surface and process-area testing
◆ National / Extended Methods: Alternative to Fraser-type secondary enrichment

📊 Interpretation Guide

Observation	Interpretation	Typical Meaning	Follow-Up
Dark brown to black broth	Presumptive positive	Esculin hydrolysis associated with Listeria growth	Subculture to PALCAM, Oxford, or ALOA
No darkening	No presumptive reaction	Listeria not detected or below recovery threshold	Interpret with full workflow context
Weak or delayed darkening	Possible low-level growth	May occur with low inoculum or stressed cells	Plate and confirm as needed

🔬 Quality Control & Performance Guidance

Typical Use:
Secondary selective enrichment
Direct enrichment of difficult samples

Incubation:
30–35°C
24–48 hours

Readout:
Dark brown to black reaction
Subculture required for isolation

Workflow Note:
Selective supplement added after cooling
Use with selective plating media

Positioning: A strong-selectivity PALCAM-based enrichment broth for food and environmental microbiology laboratories needing an additional suppression step before Listeria isolation.

📋 Technical Specifications

Catalogue Number	AS-1316
Medium Type	Selective enrichment broth
Selective System	PALCAM inhibitor principle
Base Weight	55.88 g/L
Final pH	7.2 ± 0.2 (at 25°C)
Supplement Addition	Polymyxin B + acriflavine + ceftazidime
Sterilization	121°C, 15 minutes before supplement addition
Incubation	30–35°C for 24–48 h
Prepared Complete Broth Storage	2–8°C, protected from light
Recommended Use Period	Within 1 month

🧫 Primary Applications

✓ Secondary selective enrichment after primary recovery steps
✓ Direct enrichment of heavily contaminated food or environmental samples
✓ National or extended Listeria method workflows
✓ High-throughput laboratory screening programs

⚗️ Preparation & Use Protocol

1. Suspend 55.88 g dehydrated PALCAM Broth base in 1 L purified water.
2. Heat with agitation and boil for 1 minute.
3. Autoclave at 121°C for 15 minutes.
4. Cool below 45°C and aseptically add reconstituted selective supplement.
5. Dispense into sterile tubes or bottles, inoculate, incubate, and subculture positive broths onto selective agar.

📦 Storage & Use

Prepared complete broth: Store at 2–8°C, protected from light.

Use period: Use within 1 month for best performance.

Procedure note: Positive broths should be subcultured onto PALCAM Agar, Oxford, or ALOA.

Notice: For food and environmental microbiology only.

AuSaMicS Life Science: Professional microbiology media for food safety, environmental monitoring, quality control, research, and specialized pathogen detection workflows. Product information is provided for laboratory and technical evaluation purposes only.