Description
0.5 McFarland Standard Kit
McFarland standards are commonly used in antibiotic susceptibility testing (AST) to standardize the approximate number of bacteria in a liquid suspension or culture medium.
0.5 McFarland Standard
Product Description / Application Information:
The 0.5 McFarland standard is recognized as a reference for estimating turbidity and determining the density of bacterial suspension in liquids. This standard is prepared by mixing 1% Barium Chloride (BaCl₂) and 1% Sulfuric Acid (H₂SO₄), resulting in the formation of barium sulfate precipitate that produces a uniform and reliable turbidity.
By adjusting the volumes of these two reagents, McFarland standards with different turbidity levels (usually ranging from 0.5 to 4) can be prepared, each representing a specific bacterial cell density.
Applications:
Reference for adjusting and correcting the turbidity of bacterial suspension in vials or tubes
Standardization of bacterial counts in microbiological tests
Used in antimicrobial susceptibility testing (AST)
Quality control of microbial culture media
Importance of the 0.5 McFarland Standard:
The 0.5 McFarland standard is the most commonly used concentration in microbiology laboratories and approximately corresponds to 1.5 × 10⁸ CFU/mL. The use of this standard improves accuracy, reproducibility, and comparability of test results.
