Description
General description
GranuCult® plus Deoxycholate lactose agar is a selective agar for the enumeration and isolation of Coliform bacteria from milk, water, ice cream, and other materials. The concentrations of deoxycholate and citrate are so low that the coliform bacteria can grow normally, whereas the accompanying Gram-positive bacteria are inhibited. Degradation of lactose to acid is detected by the pH indicator neutral red, which changes its color to red, and by a zone of precipitation caused by bile acid.
Application
GranuCult® plus Deoxycholate lactose agar is suitable for the enumeration and isolation of Coliform bacteria from milk, water, ice cream, and other materials.
Features and Benefits
GranuCult® offers superior granulated culture media
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
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
Appearance (clearness): clear to slightly opalescent
Appearance (colour): red-brown
pH-value (25 °C): 6.9 - 7.3
Solidification behaviour (2 hrs., 45 °C): liquid
Recovery on test medium (Escherichia coli ATCC 25922 (WDCM 00013)): ≥ 40 %
Recovery on test medium (Klebsiella pneumoniae ATCC 13883 (WDCM 00097)): ≥ 40 %
Recovery on test medium (Enterobacter cloacae ATCC 13047 (WDCM 00083)): ≥ 40 %
Recovery on test medium (Salmonella typhimurium ATCC 14028 (WDCM 00031)): ≥ 40 %
Recovery on test medium (Salmonella enteritidis ATCC 13076 (WDCM 00030)): ≥ 40 %
Recovery on test medium (Shigella flexneri ATCC 12022 (WDCM 00126)): ≥ 40 %
Recovery on test medium (Proteus mirabilis ATCC 14273): ≥ 40 %
Recovery on test medium (Enterococcus faecalis ATCC 11700): ≤ 0.01 %
Recovery on test medium (Staphylococcus aureus ATCC 25923 (WDCM 00034)): ≤ 0.01 %
Colony colour (Escherichia coli ATCC 25922 (WDCM 00013)): red
Colony colour (Klebsiella pneumoniae ATCC 13883 (WDCM 00097)): pink/red
Colony colour (Enterobacter cloacae ATCC 13047 (WDCM 00083)): pink/red
Colony colour (Salmonella typhimurium ATCC 14028 (WDCM 00031)): colourless
Colony colour (Salmonella enteritidis ATCC 13076 (WDCM 00030)): colourless
Colony colour (Shigella flexneri ATCC 12022 (WDCM 00126)): colourless
Colony colour (Proteus mirabilis ATCC 14273): colourless
Precipitate (Escherichia coli ATCC 25922 (WDCM 00013)): +
Precipitate (Klebsiella pneumoniae ATCC 13883 (WDCM 00097)): +/poor
Precipitate (Enterobacter cloacae ATCC 13047 (WDCM 00083)): +/poor
Incubation: 24 hrs.; 35 °C; aerobic.
Other Notes
Appearance of Colonies & the corresponding MicroorganismsRed, surrounded by a zone of precipitate: Lactose-positive: Escherichia coli
Pale with a pink center and surrounded by a zone of precipitate: Weakly lactose-positive: Enterobacter, Klebsiella, and others
Colorless: Lactose-negative: Salmonella, Shigella, Proteus, Pseudomonas, and other
Legal Information
GRANUCULT is a registered trademark of Merck KGaA, Darmstadt, Germany
NutriSelect is a registered trademark of Merck KGaA, Darmstadt, Germany
Disclaimer
We offer two media types: the superior granulated GranuCult® and the cost-efficient powdered NutriSelect® culture media, depending on your needs. The designations basic, plus, or prime are added to indicate the quality control level, from basic quality control to standard QC plus to prime for full regulatory compliance.
