1. What is dsDNA Copy Number Calculation?

The dsDNA copy number calculation determines the number of DNA molecules in a given volume based on concentration, volume, and molecular weight. This is essential for quantitative PCR, sequencing, and other molecular biology applications where precise DNA quantification is required.

2. How Does the Calculator Work?

The calculator uses the following equation:

Where:

• \( C \) — DNA concentration (ng/μL)
• \( V \) — Volume (μL)
• \( MW \) — Molecular weight (g/mol)
• \( 6.022 \times 10^{23} \) — Avogadro's number (molecules/mol)
• \( 10^9 \) — Conversion factor (ng to g)

Explanation: The equation converts mass concentration to molar concentration, then calculates the actual number of molecules using Avogadro's number.

3. Importance of Copy Number Calculation

Details: Accurate copy number determination is crucial for:

• Standardizing qPCR experiments
• Preparing sequencing libraries
• Creating standard curves
• Ensuring reproducibility in molecular biology experiments

4. Using the Calculator

Tips:

• Enter DNA concentration in ng/μL (from Nanodrop or Qubit)
• Enter volume in μL (typically your total sample volume)
• Enter molecular weight in g/mol (calculate as 660 g/mol × base pairs)

5. Frequently Asked Questions (FAQ)

Q1: How do I calculate molecular weight of my DNA?
A: Multiply the length in base pairs by 660 g/mol (average MW of a dsDNA base pair).

Q2: Why use ng/μL instead of other units?
A: Most spectrophotometers and fluorometers report concentration in ng/μL, making it a practical unit for this calculation.

Q3: What's a typical copy number range for qPCR?
A: Standard curves often range from 10¹ to 10⁹ copies/μL, depending on application.

Q4: Does this work for ssDNA or RNA?
A: No, this is specifically for dsDNA. For ssDNA or RNA, use different molecular weight values (330 g/mol per nucleotide).

Q5: How accurate is this calculation?
A: It's mathematically precise, but accuracy depends on your input measurements (especially concentration determination).