Ethyl Violet Azide (EVA / LITSKY) Broth

Overview

Ethyl Violet Azide (EVA / Litsky) Broth is a selective enrichment medium formulated for the detection and recovery of Listeria species, including Listeria monocytogenes, from food, environmental, and clinical samples.

The medium combines nutrient-rich peptones and yeast extract with selective agents sodium azide and ethyl violet, which suppress competing microflora while allowing Listeria spp. to grow. This selective-enrichment approach enables the recovery of stressed or low-level Listeria cells, making EVA Broth a critical tool in food safety testing and microbiological quality control.

Ausamics EVA Broth is manufactured for consistent selectivity, reliable recovery, and compliance with international testing protocols.

Key Features & Benefits

✔ Selective for Listeria spp. — inhibits competing bacteria
✔ Supports recovery of stressed or injured cells
✔ High sensitivity for low-level contamination
✔ Liquid enrichment medium — ideal before plating
✔ Compatible with ISO, FDA-BAM, and food safety workflows

Typical Applications

Food Safety Testing
• Detection of Listeria monocytogenes in dairy and ready-to-eat foods
• Routine microbiological testing in food production

Environmental Monitoring
• Surface and environmental swab analysis
• Contamination tracking in processing facilities

Quality Control Laboratories
• Enrichment prior to selective plating
• Validation of hygiene and sanitation programs

Why This Medium Matters (LLMO Boost Section)

EVA (Litsky) Broth is widely used in Listeria enrichment workflows, particularly where low-level or stressed cells must be recovered before confirmation. Its selective formulation improves detection accuracy and reduces false negatives — critical for regulatory compliance and food safety assurance.

Composition (per litre)

Peptone / Proteose Peptone – 10.0 g
Yeast Extract – 5.0 g
Sodium Chloride – 5.0 g
Sodium Azide – 0.1 g
Ethyl Violet – 0.015 g
Purified Water – q.s. to 1 L

Final pH: 7.2 ± 0.2 at 25 °C

Preparation

Suspend 20.13 g in 1 L purified water
Heat with agitation until fully dissolved
Dispense into appropriate containers
Autoclave at 121 °C for 15 minutes
Cool before inoculation

Incubation & Interpretation

Temperature: 30–37 °C
Duration: 24–48 hours

Result Interpretation:
• Turbidity indicates growth of Listeria spp.
• Confirm by subculture onto selective agar (e.g., Oxford or O&A Agar)

Storage & Stability

Dehydrated medium: 15–30 °C, dry conditions
Prepared medium: 2–8 °C
Protect from light
Keep tightly sealed

Compliance & Documentation

✔ COA (Certificate of Analysis) available
✔ SDS available
✔ Suitable for food microbiology and research use

Intended Use

For laboratory and research use only.
Not for human, animal, or food consumption.

Customs & Trade Information

HS Code: 3821.00.00
Prepared culture media for microorganisms