Hardy Diagnostics McFarland Latex Standard #0.5 provides a reliable, stable, and ready-to-use turbidity reference for adjusting bacterial suspensions to standard densities prior to antimicrobial susceptibility testing (AST) or other microbiological assays.

Each latex standard is prepared from a suspension of uniform latex particles, designed to match the optical absorbance of traditional 0.5 barium sulfate McFarland standards. However, unlike those older formulations, the latex-based design offers superior stability, homogeneity, and resistance to light degradation, providing accurate and reproducible results over a longer shelf life.

This standard represents a bacterial density equivalent to approximately 1.5 × 10⁸ CFU/mL, making it ideal for laboratories performing Kirby-Bauer disk diffusion, MIC determinations, and other quantitative microbial assays.

Features and Benefits:
• Prepared from uniform latex particles for consistent optical density
• Equivalent absorbance to barium sulfate McFarland standards
• Improved stability and resistance to clumping or light degradation
• Long shelf life and lot-to-lot reproducibility
• Ready to use — no dilution or mixing required
• Essential for antimicrobial susceptibility testing (AST) and turbidity standardization
• Compatible with manual or automated optical comparators