1. What is Copy Number Calculation?

The copy number calculation estimates relative DNA quantity in qPCR experiments using the delta Ct method. It provides a normalized measure of target DNA concentration relative to a reference.

2. How Does the Calculator Work?

The calculator uses the copy number formula:

Where:

• \( CN \) — Copy number (dimensionless)
• \( \Delta Ct \) — Difference between target and reference Ct values

Explanation: The equation assumes 100% PCR efficiency, where each cycle doubles the DNA amount. The negative exponent accounts for the inverse relationship between Ct and starting quantity.

3. Importance of Copy Number Calculation

Details: Copy number calculation is essential for gene expression studies, viral load quantification, and genetic variation analysis in molecular biology.

4. Using the Calculator

Tips: Enter the ΔCt value (target Ct - reference Ct). The value can be positive or negative depending on relative abundance.

5. Frequently Asked Questions (FAQ)

Q1: What does a CN of 1 mean?
A: A CN of 1 indicates equal quantity of target and reference DNA (ΔCt = 0).

Q2: What if my CN is greater than 1?
A: CN > 1 means the target is more abundant than the reference (negative ΔCt).

Q3: What if my CN is less than 1?
A: CN < 1 means the target is less abundant than the reference (positive ΔCt).

Q4: Does this account for PCR efficiency?
A: No, this assumes 100% efficiency. For different efficiencies, use \( (1 + E)^{-\Delta Ct} \) where E is efficiency (0-1).

Q5: How should I interpret negative ΔCt values?
A: Negative ΔCt occurs when target Ct is lower than reference Ct, indicating higher target abundance.