qPCR Efficiency Calculator
Calculate PCR efficiency from standard curve slope and optimize your qPCR assays
Calculate qPCR Efficiency
Slope from your qPCR standard curve (should be negative)
qPCR Efficiency Results
Formula used: Efficiency = (-1 + 10^(-1/slope)) × 100%
Perfect efficiency: 100% (slope = -3.322)
Acceptable range: 90-110% efficiency (slope: -3.6 to -3.1)
Efficiency Interpretation Guide
PCR Optimization Tips
Standard Curve Best Practices
- •Use ≥5 dilution points (10-fold dilutions)
- •Run at least triplicates for each point
- •Check R² correlation (should be ≥0.99)
- •Remove outliers and repeat if necessary
Common Issues & Solutions
- •Low efficiency: Check primer concentration
- •High efficiency: Check for contamination
- •Poor linearity: Verify dilution accuracy
- •Outliers: Check pipetting technique
Example Calculation
Standard Curve Analysis
Given: Standard curve slope = -3.35
Formula: Efficiency = (-1 + 10^(-1/-3.35)) × 100%
Calculation: (-1 + 10^(0.2985)) × 100%
Step: (-1 + 1.9884) × 100%
Results
PCR Efficiency: 98.84%
Amplification Factor: 1.99
Interpretation: Excellent efficiency within acceptable range
Status: ✅ PCR assay performing optimally
Reference Values
Common Slope Values
Slopes between -3.1 and -3.6 are acceptable
Understanding qPCR Efficiency
What is qPCR Efficiency?
qPCR efficiency measures how well your PCR reaction amplifies the target sequence. Perfect efficiency (100%) means the target DNA doubles in each cycle, indicating optimal primer binding and polymerase activity.
Why is it Important?
- •Validates assay reliability and accuracy
- •Ensures quantitative results are meaningful
- •Allows comparison between different assays
- •Identifies optimization needs early
Efficiency Formula
Efficiency = (-1 + 10^(-1/slope)) × 100%
Amplification Factor = 10^(-1/slope)
- Slope: From log(DNA) vs Ct plot
- -3.322: Perfect slope for 100% efficiency
- 90-110%: Acceptable efficiency range
- R² ≥ 0.99: Required correlation coefficient
Remember: Ct values should be 3.322 cycles apart for 10-fold dilutions at 100% efficiency.