1. What is Copy Number Calculation?

The copy number calculation determines the number of molecules (copies) of DNA present in a given mass, based on the molecular weight of the DNA. This is essential for molecular biology applications like PCR, sequencing, and cloning.

2. How Does the Calculator Work?

The calculator uses the following formula:

Where:

• \( C \) — Mass of DNA in grams
• \( MW \) — Molecular weight of DNA in g/mol
• \( 6.022 \times 10^{23} \) — Avogadro's number (molecules per mole)

Explanation: The formula converts the mass of DNA to moles, then multiplies by Avogadro's number to get the number of molecules.

3. Importance of Copy Number

Details: Knowing the exact copy number is crucial for accurate quantification in molecular biology experiments, ensuring proper template amounts for PCR, sequencing library preparation, and other applications.

4. Using the Calculator

Tips: Enter the mass of DNA in grams and the molecular weight in g/mol. Both values must be positive numbers. The molecular weight can be calculated as (length in bp × 650 g/mol/bp) for double-stranded DNA.

5. Frequently Asked Questions (FAQ)

Q1: How do I determine the molecular weight of my DNA?
A: For double-stranded DNA, multiply the length in base pairs by approximately 650 g/mol/bp. For single-stranded DNA, use 330 g/mol/bp.

Q2: What units should I use for the mass?
A: The calculator uses grams, but you can convert from micrograms (μg) by dividing by 1,000,000 (1 μg = 1×10⁻⁶ g).

Q3: Why is Avogadro's number used?
A: Avogadro's number (6.022×10²³) is the number of molecules in one mole of a substance, allowing conversion between mass and molecule count.

Q4: Can this be used for RNA?
A: Yes, the same formula applies to RNA, but use the appropriate molecular weight (approximately 340 g/mol per nucleotide for single-stranded RNA).

Q5: How accurate is this calculation?
A: The calculation is mathematically precise, but accuracy depends on the precision of your mass measurement and molecular weight estimation.