McFarland 3.0 Turbidity Standard

Before use, gently mix the buttle to ensure an even suspension.
Compare the bacterial suspension in a clear tube against the
McFarland 0.5 standard under adequate lighting.
Adjust the bacterial suspension by adding sterile saline or broth if the
turbidity is too high or adding more bacteria if the turbidity is too low.
Use the standardized bacterial suspension immediately for
antimicrobial susceptibility testing.
Notes:
This product is intended for laboratory use only and should not be
used for direct clinical diagnosis.
The McFarland standard must be stored in a light-protected area to
prevent degradation.
Over time, precipitation may occur; shake well before use to ensure
uniformit

McFarland 3.0 Turbidity Standard is a laboratory reference standard used to calibrate and verify bacterial suspension density for microbiological testing. It provides a reproducible turbidity equivalent to approximately 9.0 × 10⁸ CFU/mL, ensuring consistency and reliability in antimicrobial susceptibility testing and other microbiological procedures.

🏭⚗️ Production
Manufactured under controlled laboratory conditions using precisely defined concentrations of barium chloride and sulfuric acid, or equivalent stabilized formulations, to achieve accurate turbidity. Each batch is quality-checked for optical density, visual consistency, and stability against precipitation or color change. Supplied in sealed, light-protected, chemically resistant containers to maintain turbidity integrity during storage and routine laboratory use.

🔬 Properties
An opaque, uniformly turbid suspension with a milky appearance. Designed to provide stable and reproducible light-scattering characteristics when properly stored. Corresponds to McFarland standard 3.0, equivalent to an optical density of approximately 0.9 at 600 nm. Not intended for biological growth or consumption. Sensitive to prolonged light exposure, temperature extremes, and agitation that may alter turbidity distribution.

🧪 Applications
Used for standardization of bacterial inoculum density in antimicrobial susceptibility testing (AST), including disk diffusion and dilution methods. Supports quality control in clinical microbiology laboratories, ensuring consistency between tests and comparability of results across laboratories. Also applicable in microbiological training, method validation, and instrument calibration.

⚠️ Safety
For laboratory use only. Not for human or animal consumption. Avoid contact with skin and eyes; may cause irritation. Do not ingest or inhale aerosols. Handle with standard laboratory precautions, including gloves and eye protection. Store tightly closed at recommended temperatures, protected from direct light, and discard if turbidity changes, precipitation forms, or contamination is observed.