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Urea Broth (Stuart)
Differential Medium for Urease Activity

Urea Broth (Stuart) | AS-1374 | AuSaMicS Melbourne

$29.00 AUD
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AuSaMicS Life Science • Differential Media

Urea Broth (Stuart)

High-Buffer Differential Medium

Premium high-buffer differential medium for specific identification of rapid urease producers. Stuart's formulation prevents false positives from weak urease activity through precision pH buffering.

AS-1374 🧪 Differential ✓ Australian Stock 🔬 High Buffer
Same-Day Dispatch: Australian Stock Analytical Grade: Diagnostic applications Filter Sterilized: Heat-sensitive formulation

 Differential Media Specialist

High Specificity - Proteus selective
Stuart Formula - Buffer optimized
Complete Package - COA + Protocols
Fast Supply - Ships within 24h
Expert Support - Method optimization
Buffered System
Prevents false positives

 Complete Formulation & Buffer System

📋 Stuart's Formulation (per Liter)

Ingredient Concentration Primary Function Mechanism
Urea 20.0 g Primary substrate Urease hydrolysis → NH₃ + CO₂
Monopotassium Phosphate 9.1 g Primary buffer High-capacity pH stabilization
Disodium Phosphate 9.5 g Secondary buffer Synergistic buffer maintenance
Yeast Extract 0.1 g Minimal nutrition Vitamins, trace elements
Phenol Red 0.01 g pH indicator Visual shift pH 6.8→8.1+ (orange→pink)

 Stuart's High-Buffer System Advantage

Buffer Resistance
18.6 g total phosphates resist weak urease pH shifts
High Specificity
Only rapid, strong urease triggers color change
Minimal Nutrition
Low yeast extract prevents growth interference
Stuart's Logic:
High Buffer Capacity (18.6 g phosphates) + Minimal Nutrition

Rapid Urease Only = No False Positives
Key vs. Christensen: Stuart's 9x higher buffer capacity (18.6g vs 2.0g phosphates) eliminates weak urease false positives from Enterobacteriaceae

Complete Urease Testing Portfolio Analysis

Medium Format Buffer Capacity Detection Profile Target Organisms Primary Advantage
Urea Broth (Stuart) Liquid broth 🔵🔵🔵 High (18.6g) Low/Specific Rapid urease (Proteus) Prevents false positives
Urea Agar (Christensen) Solid slant 🔵 Low (2.0g) Very High All urease producers Detects weak activity
Rapid Urea Broth Liquid broth None/Minimal Maximum Ultra-rapid screening Results in 2-4 hours
CLO Test (Biopsy) Rapid gel 🔵 Moderate H. pylori specific Helicobacter pylori Gastric biopsy POC
Urea-Indole Medium Dual test broth 🔵 Moderate Moderate sensitivity Combined testing Urease + Indole together
Urease Dipsticks Paper strip Built-in reagents Good sensitivity Point-of-care Portable, rapid

⚖️ Strategic Medium Selection for Urease Testing

✅ Stuart's Broth Advantages

  • Superior Specificity: Buffer system filters weak urease
  • Proteus Specialist: Ideal for UTI pathogen ID
  • Clear Results: Distinct pink color change
  • Standardized Method: USP/EP compliance
  • Liquid Format: Enhanced reactivity
  • Quality Control: Reproducible results

⚠️ Method Considerations

  • Weak Urease Miss: May give false negatives for slow producers
  • Filter Sterilization: Cannot autoclave due to urea
  • Heavy Inoculum: Requires concentrated cell mass
  • Storage Sensitivity: Prepared medium stability
  • Cost Factor: Higher than unbuffered media

🎯 Method Selection Guide

  • Proteus Confirmation: Stuart's Broth (definitive)
  • Comprehensive Screen: Christensen Agar (all urease)
  • Emergency UTI: Rapid Urea Broth (2-4h)
  • H. pylori Testing: CLO Test (biopsy)
  • Point-of-Care: Dipstick methods

📊 Application Performance Matrix

Application Stuart's Broth Christensen Agar Critical Factor
UTI Pathogen ID Excellent Good Proteus specificity
Comprehensive Urease Fair Excellent Weak urease detection
Quality Control Excellent Excellent Standardized methods
Research Applications Excellent Good Liquid format advantage
Clinical Diagnosis Excellent Excellent Complementary approaches
Cost Effectiveness Good Excellent Buffer system cost

🔬 Stuart's Method Quality Control

Positive Control:
Proteus mirabilis ATCC 25933
Cerise-pink in 2-4 hours
Negative Control:
Escherichia coli ATCC 25922
Remains orange-yellow
Buffer Verification:
pH 6.8 ± 0.2 maintained
No weak urease false positives
Specificity Test:
Klebsiella pneumoniae
Should remain negative/faint
Critical Success Factor: Stuart's buffer system prevents false positives from weak urease producers. Only rapid, strong urease activity (Proteus-type) overcomes the buffer capacity for positive results.

📋 Technical Specifications

Catalogue Number AS-1374
Dehydrated Weight 38.62 g/L
Final pH 6.8 ± 0.2 (at 25°C)
Buffer Capacity High (18.6g phosphates)
Sterilization Filter only (0.2μm)
Format Dehydrated powder
Grade Analytical Grade
Shelf Life 3 years

 Target Activity Profile

  • Proteus mirabilis - Strong positive (cerise)
  • Proteus vulgaris - Strong positive (cerise)
  • Morganella morganii - Strong positive
  • Escherichia coli - Negative (orange)
  • Klebsiella spp. - Weak/negative (filtered)

🧪 Key Applications

  • UTI Pathogen ID: Proteus confirmation
  • Differential Diagnosis: Enterobacteriaceae
  • Quality Control: Urease testing validation
  • Research Applications: Liquid format studies
  • Clinical Laboratories: Confirmatory testing

⚗️ Filter Sterilization Protocol

  1. 1 Dissolve 38.62g in 1L cold water
  2. 2 Mix completely (avoid heating)
  3. 3 Filter sterilize through 0.2μm
  4. 4 Aseptically dispense into tubes

📦 Storage & Handling

  • Dehydrated: 15-30°C, dry conditions
  • Prepared medium: 2-8°C, 1 week max
  • Light sensitive: Protect phenol red
  • ⚠️ No autoclaving: Urea degradation

🧪 Complete Urease Testing System

Urease Testing Media Portfolio

Urea Agar (Christensen)

Comprehensive urease testing

View Product
Rapid Urea Broth

Ultra-rapid screening

View Product
CLO Test Kit

H. pylori detection

View Product
Urea-Indole Medium

Combined testing

View Product

Supporting Laboratory Products

Phenol Red Indicator

pH indicator solution

View Product
Phosphate Buffers

Buffer system components

View Product
Urea Substrate

High purity urea

View Product
Filter Sterilization

0.2μm membrane filters

View Product

Biochemical Testing Systems

API 20E Strips

20-test identification

View Product
Indole Reagent

Kovac's reagent

View Product
Catalase Reagent

H2O2 solution

View Product
Quality Control Strains

ATCC reference cultures

View Product

Need Differential Media Support?

Our differential media specialists can help optimize your urease testing protocols and buffer systems

For laboratory and research use only. Not intended for food, feed, household, cosmetic, therapeutic, or personal use.
AuSaMicS Pty Ltd • ABN: 56 676 640 467 • 31 Longview CT, Thomastown, VIC 3074, Australia
Same-day dispatch • Australian stock • Analytical grade • Stuart's protocols included

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