BD 278850 - Difco XLD Agar, 500 g Bottle, Selective Differential Medium for Isolation of Enteric Pathogens, EA
The BD 278850 - BD Difco Xylose Lysine Deoxycholate (XLD) Agar is a high-quality, selective, and differential dehydrated culture medium formulated for the isolation and identification of Salmonella and Shigella species from clinical, food, and environmental samples. Produced by Becton Dickinson (BD) under the Difco brand, this 500 g bottle of XLD Agar provides a dependable formulation that delivers reproducible results across a broad range of microbiological applications. The medium incorporates xylose, lysine, deoxycholate, lactose, sucrose, and phenol red, allowing precise differentiation between enteric bacteria based on carbohydrate fermentation, decarboxylation of lysine, and hydrogen sulfide (H2S) production.
Designed for both routine diagnostic testing and research, BD Difco XLD Agar is a trusted choice for laboratories requiring consistent recovery of pathogenic enteric bacteria while inhibiting commensal intestinal flora.
Key Benefits
The BD Difco XLD Agar provides superior clarity, selectivity, and diagnostic accuracy. Major benefits include:
- High selectivity: Sodium deoxycholate selectively inhibits Gram-positive organisms, promoting recovery of Gram-negative enteric bacteria.
- Distinct differentiation: Enables clear distinction of Salmonella (red colonies with black centers) and Shigella (red colonies without black centers) from fermentative coliforms (yellow colonies).
- Reliable and reproducible results: Rigorously quality-controlled for consistent color response and colony morphology.
- Convenient dehydrated formulation: The 500 g bottle allows laboratories to prepare customized volumes of agar as needed.
- Broad utility: Applicable in clinical, food safety, and environmental testing for enteric pathogen detection.
Compatibility and Applications
The BD 278850 XLD Agar is compatible with standard bacteriological procedures and equipment. It is widely used in:
- Clinical laboratories for detection of Salmonella and Shigella from stool specimens.
- Public health and food testing facilities for contamination screening.
- Environmental laboratories for monitoring enteric bacteria in water or waste samples.
- Pharmaceutical and industrial microbiology quality control testing.
This medium is suitable for both manual inoculation and automated plating systems, ensuring flexibility in high-throughput or research laboratory settings.
Usage Guidelines
To prepare, suspend 55 g of BD Difco XLD Agar powder in 1 liter of purified or distilled water. Heat gently with frequent agitation until completely dissolved. Boil for one minutedo not autoclave. Pour the medium into sterile Petri dishes and allow to solidify. Inoculate the surface and incubate at 3537C for 1824 hours. Examine for colony color and morphology:
- Salmonella spp.: Red colonies with black centers (H2S positive).
- Shigella spp.: Red colonies without black centers (H2S negative).
- Coliforms and non-pathogens: Yellow colonies due to acid production from sugar fermentation.
Do not overheat or autoclave the medium, as this can reduce its selectivity and differential performance.
Certifications, Safety Standards, and Regulatory Approvals
The BD Difco XLD Agar is produced under ISO 13485:2016 and ISO 9001:2015-certified quality management systems and meets ISO 11133 requirements for microbiological media. It complies with FDA, CE, and USP standards for culture media used in clinical and food microbiology. Each lot undergoes performance testing for growth promotion, inhibition, and selectivity using control strains including Salmonella enterica serotype Typhimurium (ATCC 14028), Shigella flexneri (ATCC 12022), and Escherichia coli (ATCC 25922). These tests ensure consistent media performance across all applications.
Comparison with Competitor Products
Compared to other enteric selective media, such as Hektoen Enteric Agar or MacConkey Agar, BD Difco XLD Agar offers improved differentiation through the inclusion of xylose and lysine, which enhance the separation of Salmonella and Shigella from other intestinal flora. While Hektoen Agar can produce less distinct colony color contrast, BD XLD Agar yields more vivid differentiation, particularly for H2S-producing organisms. Its balanced selectivity minimizes overgrowth of non-pathogenic flora, making it the preferred medium for routine Salmonella surveillance and confirmation testing.
Typical User Profile and Application Scenarios
This product is intended for microbiologists, diagnostic technologists, and quality control professionals working in:
- Clinical microbiology labs diagnosing gastrointestinal infections.
- Food safety and quality control labs detecting contamination in meat, poultry, and dairy products.
- Environmental monitoring programs in water testing and sanitation control.
- Research institutions studying enteric bacterial pathogenesis or antimicrobial resistance.
The 500 g bottle format provides cost efficiency and flexibility for medium preparation in laboratories of varying workload capacities.
Best Practices for Use and Maintenance
Store the dehydrated BD Difco XLD Agar at 225C in a tightly closed container, protected from moisture and direct sunlight. Use only high-quality, distilled water for reconstitution. Once prepared, pour plates should be stored at 28C in sealed packaging and used within four weeks for optimal performance. Always label media with preparation and expiration dates. Discard expired or contaminated media according to biohazard disposal protocols.
Regulatory and Safety Information
The BD 278850 - BD Difco XLD Agar (500 g Bottle) is classified as an in vitro diagnostic (IVD) reagent and meets FDA, CE, and ISO safety requirements for professional laboratory use. The medium is non-toxic, DEHP-free, and latex-free. It contains no hazardous ingredients under standard laboratory handling conditions. A Safety Data Sheet (SDS) is available from BD upon request, detailing composition, safety precautions, and disposal procedures. Use appropriate personal protective equipment (PPE) and follow institutional biosafety standards when handling samples and cultures.
How to Order
To order the BD 278850 - BD Difco XLD Agar (500 g Bottle), add the item to your cart and complete checkout through CIA Medical. We offer competitive pricing, prompt shipping, and full support for clinical, food safety, and research laboratories. For bulk orders, Certificates of Analysis, or technical data sheets, contact CIA Medicals customer service team at (312) 275-5850 or use the contact form on this page. Our representatives are available to assist with product availability, documentation, and laboratory compatibility inquiries.
