Mannitol Salt Agar (MSA) | Selective & Differential Culture Medium
Mannitol Salt Agar (HiMedia Code: M118) is a specialized selective and differential growth medium widely used in diagnostic bacteriology and public health laboratories. Specifically designed to isolate and differentiate presumptive pathogenic staphylococci—most notably Staphylococcus aureus—from clinical specimens, food products, cosmetics, and environmental surfaces, it is an essential diagnostic reagent across hospital pathology departments, pharmaceutical quality control units, and university microbiology faculties throughout Bangladesh.
Isolating staphylococci from heavily contaminated specimens (such as skin swabs, pus, or food samples) requires a growth medium capable of suppressing unwanted Gram-negative bacteria and non-halotolerant organisms. Mannitol Salt Agar achieves this selective inhibition through a high sodium chloride (NaCl) concentration of 7.5%, which tolerates halotolerant staphylococci while inhibiting most other bacteria. Simultaneously, it provides differential diagnostics through the carbohydrate D-mannitol and the pH indicator phenol red. Pathogenic Staphylococcus aureus ferments D-mannitol, releasing acidic metabolic byproducts that lower the local agar pH and shift the phenol red indicator from red to bright yellow. Non-pathogenic staphylococci (such as Staphylococcus epidermidis) do not ferment mannitol, leaving the surrounding agar red or pink.
Supplied as a free-flowing, homogeneous pinkish-red dehydrated powder, it dissolves efficiently in distilled water (typically 111.02 g/L) and autoclaves to a clear to slightly opalescent red gel. Victor Scientific Co. supplies authentic HiMedia culture media, analytical reagents, and laboratory apparatus nationwide with batch traceability and dependable delivery across all 64 districts of Bangladesh.
✹ Key Features
Authentic HiMedia Quality (Code: M118)
Manufactured to stringent international microbiological benchmarks, ensuring consistent high salt tolerance and sharp color-change differentiation.
High-Salinity Selective Inhibition
Contains 7.5% sodium chloride to selectively suppress non-halotolerant bacteria while facilitating the growth of staphylococci.
Clear Mannitol Fermentation Indicator
Incorporates D-mannitol and phenol red to distinguish pathogenic mannitol-fermenting S. aureus (yellow colonies) from non-fermenters (red/pink colonies).
Nutrient-Rich Peptone Base
Enriched with proteose peptone, meat extract, and casein hydrolysate to supply essential amino acids, nitrogen, and vitamins for robust bacterial growth.
Convenient Preparation Ratio
Requires suspending 111.02 grams in 1,000 ml of purified distilled water, boiling to dissolve completely, and autoclaving at 121°C for 15 minutes.
Moisture-Resistant HDPE Packaging
Packaged in a 500-gram hermetically sealed container designed to safeguard the dehydrated powder against ambient humidity and degradation.
✹ Applications
- Clinical diagnostic isolation and identification of Staphylococcus aureus from pus, wound swabs, and clinical specimens
- Food safety and dairy hygiene testing for staphylococcal food poisoning hazard evaluation
- Pharmaceutical bioburden testing and cosmetic product microbial limit screening for pathogenic staphylococci
- Hospital environmental surveillance, personnel screening, and cleanroom bioburden monitoring
- Academic undergraduate and postgraduate laboratory practicals in medical microbiology and infectious disease study
✹ Why Choose Mannitol Salt Agar?
- Dual-action selectivity and differentiation allow simultaneous isolation and presumptive identification of S. aureus on a single plate.
- Distinct color contrast (yellow versus red) enables rapid, unambiguous visual interpretation within 24 to 48 hours.
- Highly soluble powder boils smoothly into a uniform solution without clumping, reducing preparation time.
- Genuine institutional procurement and dependable stock availability backed by Victor Scientific Co.
✹ Benefits
- Enhances clinical and industrial diagnostic efficiency by eliminating false-positive growth from contaminating non-halotolerant flora.
- Maximizes laboratory cost-efficiency through high-yield 500g packaging capable of producing over 4.5 liters of finished testing media.
- Reduces procedural errors with certified formulation standards and clear technical documentation.
- Backed by dependable nationwide distribution and technical support through Victor Scientific Co.
✹ About Victor Scientific Co.
Victor Scientific Co. provides quality laboratory equipment, measuring instruments and scientific tools in Bangladesh. We supply reliable products for educational institutions, industries, laboratories and professional users.