1.05290

XLD Agar (nach harm. EP/USP/JP)

GranuCult^® prime, EP, USP, JP, granular, for Salmonella spp., pkg of 500 g

• Synonym(e): Xylose-lysine-deoxycholate agar
• NACRES: NA.74
• UNSPSC Code: 41106200
• Manufacturer/tradename: GranuCult^® prime
• Agency: EP, JP, USP
• Ph: 7.2-7.6 (25 °C, 55.2 g/L in H₂O)
• Form: granular
• Suitability: Salmonella spp.
• Application(s): microbiology; pharmaceutical

Eigenschaften

• Quality Segment: 200
• agency: EP, JP, USP
• description: Xylose-lysine-deoxycholate agar for microbiology
• sterility: non-sterile
• form: granular
• packaging: pkg of 500 g
• manufacturer/tradename: GranuCult^® prime
• technique(s): microbiological culture: suitable
• color: red
• pH: 7.2-7.6 (25 °C, 55.2 g/L in H₂O)
• solubility: 55.2 g/L
• application(s): microbiology; pharmaceutical
• storage temp.: 15-25°C
• suitability: Salmonella spp.

Beschreibung

General description

XLD Agar (Xylose Lysine Deoxycholate Agar) is a selective and differential medium used for isolating and differentiating pathogenic Enterobacteriaceae, particularly Salmonella and Shigella species. The media consists of yeast extract for vitamins, peptic digest of animal tissue for nitrogenous compounds, and agar as a solidifying agent. Xylose, lactose, and sucrose serve as fermentable carbohydrates. L(+)-lysine detects lysine-decarboxylase activity, causing alkalization and a red-violet color. Sodium thiosulfate and ferric ammonium citrate react with hydrogen sulfide to form black iron sulfide precipitates in colonies. Sodium deoxycholate inhibits coliform bacteria, ensuring selectivity.

Application

XLD Agar has diverse applications across industries. In the food and beverage sector, it is used to detect Salmonella and Shigella in meat, dairy, and processed foods, ensuring compliance with safety standards. In water quality testing, it identifies pathogenic Enterobacteriaceae to ensure the safety of drinking water. The pharmaceutical industry employs XLD Agar for microbial testing to detect contamination in products, adhering to pharmacopeial standards.

Features and Benefits

• Safe and sustainable due to reduced risks associated with fine dust and toxic substance inhalation, resulting in a safer work environment
• Excellent wettability, solubility, and free-flowing properties
• Convenient, with minimal component separation and clumping, even under warm or humid conditions
• High batch-to-batch reproducibility
• Prolonged shelf life of up to five years
• A high number of test strains exceeding all regulatory demands
• Granulation technology allows many supplements to be included, with no need to add these separately

Analysis Note

Aussehen (Klarheit): klar
Aussehen (Farbe): rot
pH-Wert (25 °C): 7,2–7,6
Typische Zusammensetzung (g/Liter): Hefeextrakt 3,0; Natriumchlorid 5,0; D(+)-Xylose 3,5; Lactose 7,5; Saccharose 7,5; L(+)-Lysin 5,0; Natriumdesoxycholat 2,5; Natriumthiosulfat 6,8; Ammoniumeisen(III)-citrat 0,8; Phenolrot 0,08; Agar-Agar 13,5.
Wachstumsprüfung gemäß der harmonisierten Methode der EP, USP und JP.
Inokulum auf Referenzmedium (Salmonella typhimurium ATCC 14028 (WDCM 00031)): 10–100
Inokulum auf Referenzmedium (Salmonella Abony NCTC 6017): 10–100
Koloniezahl (Salmonella typhimurium ATCC 14028 (WDCM 00031)):
Koloniezahl (Salmonella Abony NCTC 6017):
Wiederfindung auf Testmedium (Salmonella typhimurium ATCC 14028 (WDCM 00031)): ≥ 50 %
Wiederfindung auf Testmedium (Salmonella Abony NCTC 6017): ≥ 50 %
Koloniefarbe (Salmonella typhimurium ATCC 14028 (WDCM 00031)): rot
Koloniefarbe (Salmonella Abony NCTC 6017): rot
Schwarzes Zentrum (Salmonella typhimurium ATCC 14028 (WDCM 00031)): +
Schwarzes Zentrum (Salmonella Abony NCTC 6017): +
Wachstum (Escherichia coli ATCC 8739 (WDCM 00012)): nicht vorhanden bis sehr gut
Koloniefarbe (Escherichia coli ATCC 8739 (WDCM 00012)): gelb
Mediumfarbe (Escherichia coli ATCC 8739 (WDCM 00012)): gelb
Präzipitat (Escherichia coli ATCC 8739 (WDCM 00012)): +
Inkubation: Salmonella 18 Std.; 30–35°C; E. coli bis zu 48 Std.
Die obigen Informationen sind aktuell zum Zeitpunkt der Veröffentlichung und können ohne Vorankündigung geändert werden (ausgenommen sind Kunden, die einen Änderungskontrollvertrag mit unserem Unternehmen abgeschlossen haben). Die Informationen bzw. das Format können jederzeit und auf jede Art und Weise geändert werden, wenn interne Unternehmensangelegenheiten oder Standardbestimmungen dies vorsehen.

Other Notes

Wir bieten zwei Medientypen an: das höherwertige granulierte GranuCult^® und das kostengünstige pulverförmige NutriSelect^® Kulturmedium, je nach Anforderung bei der jeweiligen Anwendung.
Die Bezeichnungen „Basic“, „Plus“ oder „Prime“ werden ergänzt, um das Qualitätssicherungsniveau anzugeben, von der Basis-Qualitätssicherung (Basic) über die Standard-Qualitätssicherung (Plus) bis zur Premium-Qualitätssicherung (Prime) für vollständige regulatorische Konformität.

Typical colonies of Salmonella exhibit a black center surrounded by a translucent red zone due to indicator color changes. H₂S-negative Salmonella, such as Salmonella paratyphi A, grow as pink colonies with a dark pink center. The degradation of xylose results in acidification, causing the medium to turn yellow. Strains with lysine-decarboxylase activity convert L(+)-lysine into cadaverine, causing alkalization and a red-violet coloration of the medium. This activity neutralizes the acids produced during xylose degradation, resulting in a red-violet medium. Lactose and sucrose are added to differentiate lysine-decarboxylase-positive coliform bacteria from Salmonella, as their acid formation cannot be neutralized by cadaverine, leaving the medium yellow. Deoxycholate inhibits coliform bacteria growth, while thiosulfate and iron (III) salt react with hydrogen sulfide to form black iron sulfide precipitates in colonies. Sodium thiosulfate is reduced by Salmonella and other sulfate-reducing bacteria to H₂S, which reduces ferric ammonium citrate to black iron sulfide. This reaction is more pronounced under alkaline conditions, but H₂S-producing bacteria that form acids from lactose or sucrose, such as Citrobacter spp. and Proteus spp., may show weaker black centers. Salmonella typhi colonies often appear yellow-orange or pink.

Legal Information

GRANUCULT is a registered trademark of Merck KGaA, Darmstadt, Germany

NutriSelect is a registered trademark of Merck KGaA, Darmstadt, Germany

Sicherheitshinweise

• Lagerklasse: 11 - Combustible Solids
• wgk: WGK 3