Colony Counting Calculator (CFU/mL)
Calculate colony forming units per mL (CFU/mL) from colony counts, dilution factor, and volume plated.
How to Use the Colony Counting Calculator
- Count the colonies on your agar plate.
- Enter the dilution factor used (e.g., 10000 for a 10⁻⁴ dilution).
- Enter the volume plated in mL (e.g., 0.1 mL).
- Click Calculate to get CFU/mL and log₁₀ CFU/mL.
حالات الاستخدام
- •Enumerating bacterial load in food safety and water quality testing.
- •Quantifying antibiotic kill curves in microbiology experiments.
- •Monitoring fermentation cultures and probiotic products.
الصيغة
Formula: CFU/mL = colony count / (dilution factor × volume plated in mL).
الأسئلة الشائعة
What is CFU/mL?
CFU/mL (colony forming units per milliliter) is a measure of viable microbial density. Each colony on an agar plate is assumed to originate from a single viable cell or cell cluster.
Which dilutions give the most accurate counts?
Plates with 30–300 colonies are considered statistically reliable (TNTC/TFTC rules). Use serial dilutions to achieve counts in this range.
Disclaimer
For educational and microbiological research purposes only. Results assume proper aseptic technique, incubation conditions, and that only one colony arises from one cell.