Koser Citrate Medium | Differential Broth for IMViC Testing

$39.00 AUD

AuSaMicS Life Science • Culture Media

Koser Citrate Medium

Liquid medium for the differentiation of Coliform bacteria

Koser Citrate Medium is a chemically defined broth used to differentiate Escherichia coli from the Enterobacter-Klebsiella group based on citrate utilization. It is a critical component in water testing and the identification of enteric bacilli.

AS-1262 Differential Broth ✓ Water Quality Testing 🧫 IMViC Component

🔬 Target Use: Coliform differentiation 🧪 Reaction: Visible turbidity (Positive) 📄 Available: COA + TDS + SDS

Differentiation Logic

Sodium Citrate - sole carbon source

Ammonium Salts - sole nitrogen source

Clear Broth - easy turbidity reading

Incubation - 35°C for up to 4 days

Reliable - specific for fecal coliforms

IMViC Standard

The "C" in the IMViC series for enteric identification

🔬 Product Overview

Koser Citrate Medium is designed to test the ability of an organism to utilize sodium citrate as its only carbon source and ammonium salts as its only nitrogen source. This is a classic differential test used primarily in the identification of the Enterobacteriaceae.

Unlike Simmons Citrate Agar, which contains a pH indicator (Bromothymol Blue), Koser Citrate is a clear broth. Growth is indicated by the development of turbidity.

Fecal coliforms like Escherichia coli generally do not grow in this medium (negative), while other coliforms like Enterobacter aerogenes utilize the citrate and produce visible growth (positive).

⚗️ Intended Use

Used for the differentiation of fecal coliforms from non-fecal coliforms in water, dairy, and food microbiology. It is an essential part of the IMViC (Indole, Methyl Red, Voges-Proskauer, and Citrate) test battery for the classification of Gram-negative enteric bacilli.

🧫 Applications

🌊 Water Microbiology

Determining fecal contamination by distinguishing E. coli from other citrate-positive environmental coliforms.

🧪 Biochemical Profiling

Part of standardized taxonomic identification protocols for the Enterobacteriaceae family.

📊 Key Features

Chemically Defined
Strict nutrient control for accurate metabolic assessment.

Simple Interpretation
Clear results: Turbid (Positive) vs. Clear (Negative).

High Specificity
Optimized for standard coliform differentiation methods.

🧪 Composition (per litre)

Component	Amount
Sodium Ammonium Phosphate	1.5 g
Monopotassium Phosphate	1.0 g
Magnesium Sulfate	0.2 g
Sodium Citrate	3.0 g

Final pH: 6.7 ± 0.2 at 25°C

🧭 Preparation

Suspend 5.70 g of dehydrated medium in 1 L purified water.
Stir well and heat slightly if necessary to dissolve completely.
Dispense into tubes or flasks.
Autoclave at 121°C for 15 minutes.
Note: To avoid carry-over of nutrients, use a light inoculum from a saline suspension or a needle touch from a pure culture.

📋 Technical Specifications

Product Name	Koser Citrate Medium
Catalogue Number	AS-1262
Medium Type	Differential Broth
Target Organisms	Coliform Bacteria
Final pH	6.7 ± 0.2
Incubation	35°C for 24–96 hours
Storage	10–30°C (Dry Medium)
HS Code	3821.00.00

✅ Interpretation

Positive (+): Visible growth (turbidity). E.g., E. aerogenes.
Negative (-): No growth (clear). E.g., E. coli.

⚠️ Important Notes

Use a very light inoculum. Adding organic matter from the previous medium can lead to false-positive growth.

📄 Documentation

Technical Data Sheet (TDS)

Certificate of Analysis (COA)

Safety Data Sheet (SDS)

🧬 Related AuSaMicS Products

Simmons Citrate Agar

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