BD Difco™ Agar, Technical

Description

• Technical Agar is suitable for many bacteriological applications
• This agar is not highly processed, has broader technical specifications than other agars and is not recommended for growth of fastidious organisms
• It shows good cultural response (in nutrient broth) to Escherichia coli 25922 and Staphylococcus aureus 25923
• Loss on Drying (LOD): ≤20% Ash(%): ≤6.5% Calcium μg/g (ppm): ≤3,000 ppm Magnesium μg/g (ppm): ≤1,300 ppm Melting Point: ≤85°C Gelation Point: 32–39°C Gel Strength: 613g/cm 3 pH (1.5% solution, 25°C): 5.9 Spore count: 4,300 CFU/g Standard plate count: 2,725 CFU/g Inorganics: Calcium 0.110%, Chloride 0.172%, Cobalt <0.001%, Copper <0.001%, Iron 0.002%, Lead <0.001%, Magnesium 0.093%, Manganese <0.001%, Nitrate <0.005%, Phosphate 0.015%, Potassium 0.124%, Sodium 0.932%, Sulfate 0.367%, Sulfur 0.646%, Tin <0.001%, Zinc <0.001% Agar is a phycocolloid extracted from a group of red-purple marine algae (Class Rhodophyceae)
• Agar is the gelling agent of choice because it remains firm at growth temperatures for many pathogens
• It is also resistant to a breakdown by bacterial enzymes
• Agar melts at a different temperature than that at which it solidifies, a property known as hysteresis
• It is generally resistant to shear forces; however, different agars may have different gel strengths
• Agar is typically used in a final concentration of 1–2% for solidifying culture media.