1. What is DNA Copy Number?

DNA copy number refers to the number of copies of a particular DNA sequence present in a given volume or mass of sample. It's a fundamental measurement in molecular biology, particularly in quantitative PCR, next-generation sequencing, and other nucleic acid quantification techniques.

2. How Does the Calculator Work?

The calculator uses the DNA copy number formula:

Where:

• \( CN \) — Copy number (dimensionless)
• \( C \) — Concentration (g/L)
• \( NA \) — Avogadro's number (6.022 × 10²³ /mol)
• \( MW \) — Molecular weight (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 determination is essential for experimental design in molecular biology, ensuring proper template amounts in PCR reactions, standard curve preparation, and absolute quantification studies.

4. Using the Calculator

Tips: Enter concentration in g/L and molecular weight in g/mol. Both values must be positive numbers. The result is given in copies per liter.

5. Frequently Asked Questions (FAQ)

Q1: What is Avogadro's number?
A: Avogadro's number (6.022 × 10²³) is the number of particles (atoms, molecules, etc.) in one mole of substance.

Q2: How do I determine molecular weight?
A: For DNA, MW can be calculated as (number of bases × 607.4) + 157.9 g/mol, accounting for the phosphate backbone.

Q3: Why is copy number important in qPCR?
A: Knowing the exact copy number allows for absolute quantification of target sequences and preparation of accurate standard curves.

Q4: Can this be used for RNA?
A: Yes, the same formula applies for RNA copy number calculation, using the appropriate molecular weight.

Q5: How to convert from molar concentration?
A: If you have molar concentration (M), simply multiply by Avogadro's number to get copies/L (CN = M × NA).