MIC (Minimum Inhibitory Concentration) Calculator
Determine the Minimum Inhibitory Concentration (MIC) using an intetive 96-well microtiter plate row simulation.
Serial Dilution Setup
Enter starting concentration and mark growth status per well.
Minimum Inhibitory Concentration (MIC)
EUCAST / CLSI Guidelines
Compare calculated MIC values against CLSI/EUCAST clinical breakpoints to classify strains as Susceptible (S), Intermediate (I), or Resistant (R).
CLSI Antimicrobial Susceptibility Breakpoints (EUCAST Reference)
| Antibiotic Agent | Target Organism | Susceptible Breakpoint (S) | Resistant Breakpoint (R) |
|---|---|---|---|
| Ampicillin | Escherichia coli | ≤ 8 µg/mL | ≥ 32 µg/mL |
| Vancomycin | Staphylococcus aureus | ≤ 2 µg/mL | ≥ 16 µg/mL |
| Ciprofloxacin | Pseudomonas aeruginosa | ≤ 0.5 µg/mL | ≥ 2 µg/mL |
Methodology & Equations
Dilution Progression Formula
Calculates concentration at well step n where C₀ is starting concentration and Factor is dilution ratio (e.g. 2 for 2-fold).
MIC Determination Criteria
Finds lowest drug concentration preventing bacterial growth.
Frequently Asked Questions
What is Minimum Inhibitory Concentration (MIC)? ▼
The Minimum Inhibitory Concentration (MIC) is the lowest concentration of an antimicrobial drug or substance that completely inhibits visible growth of a microorganism in vitro.
How is MIC measured using broth microdilution? ▼
A serial dilution (commonly 2-fold) of an antibiotic is prepared across a 96-well microtiter plate row. A standardized microbial inoculum (5 × 10⁵ CFU/mL) is added. After incubation, MIC is the lowest drug concentration showing no visible turbidity (clear well).
What is the difference between MIC and MBC? ▼
MIC measures growth inhibition (bacteriostatic effect), whereas Minimum Bactericidal Concentration (MBC) measures actual microbial killing (≥ 99.9% kill).