1. What is the NEB Copy Number Equation?

The NEB Copy Number equation calculates the number of DNA molecules per microliter based on DNA concentration and length. It's essential for molecular biology applications like PCR, cloning, and sequencing.

2. How Does the Calculator Work?

The calculator uses the NEB Copy Number equation:

Where:

• \( CN \) — Copy number (copies/μL)
• \( C \) — DNA concentration (ng/μL)
• \( L \) — DNA length (base pairs)
• \( 6.022 \times 10^{23} \) — Avogadro's number
• \( 660 \) — Average molecular weight per base pair (g/mol)

Explanation: The equation converts mass concentration to molar concentration and then to molecule count using Avogadro's number.

3. Importance of Copy Number Calculation

Details: Accurate copy number calculation is crucial for determining DNA input amounts in experiments, ensuring proper stoichiometry in reactions, and standardizing experimental conditions.

4. Using the Calculator

Tips: Enter DNA concentration in ng/μL and length in base pairs. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is 660 g/mol used for base pairs?
A: This is the average molecular weight of a DNA base pair (dNTP), accounting for different nucleotide compositions.

Q2: How accurate is this calculation?
A: It provides a theoretical estimate. Actual copy numbers may vary slightly due to DNA purity and exact base composition.

Q3: Can I use this for RNA?
A: For RNA, use 340 g/mol as the average molecular weight per nucleotide instead of 660 g/mol.

Q4: What's a typical copy number range for PCR?
A: Most PCR reactions use 10^3-10^6 copies per reaction, but optimal amounts depend on the specific application.

Q5: How does DNA length affect copy number?
A: Longer DNA molecules at the same concentration will have fewer copies than shorter molecules because each molecule weighs more.