DNA Copy Number Calculator
Calculate the number of DNA molecules from concentration, mass, or molecular weight
🧬 Input Parameters
📚 DNA Copy Number Concepts
Copies = (Mass × Nₐ) / (Length × MWₐᵥₑᵣₐgₑ)
Basic formula for DNA copy number calculation
Key Constants:
- • Avogadro’s Number: 6.022 × 10²³ molecules/mol
- • dsDNA MW/bp: ~660 g/mol (average)
- • ssDNA MW/bp: ~330 g/mol (average)
- • RNA MW/bp: ~340 g/mol (average)
📊 Calculation Results
DNA Copy Number
9.11 × 10¹¹
Total Mass
1.00 μg
Molecule Weight
660 kDa
Moles of DNA
1.51 × 10⁻¹² mol
Calculation Steps
🔍 Applications
qPCR Standards
10⁶-10¹⁰ copies/μL
NGS Libraries
1-100 ng/μL
Cloning
10-100 ng
PCR
1 pg-1 ng
🧬 What is DNA Copy Number?
DNA copy number refers to the number of molecules of a specific DNA fragment in a given sample. It’s crucial for quantitative applications like qPCR, digital PCR, and next-generation sequencing.
The calculation considers the molecular weight of DNA, which depends on the number of base pairs and whether it’s single or double-stranded.
MW_dsDNA = Length × 660 g/mol
Molecular weight of double-stranded DNA
⚖️ Calculation Methods
DNA copy number can be calculated from different starting points:
- ✓ Concentration + Volume: Most common method
- ✓ Mass: Direct mass measurement
- ✓ Molecule Count: Reverse calculation
- ✓ Optical Density: Using A260 measurements
Copies = (C × V × Nₐ) / (L × MW)
From concentration and volume
🔍 Practical Applications
Accurate copy number calculation is essential for:
- • qPCR standard curve preparation
- • Digital PCR absolute quantification
- • NGS library quantification
- • Molecular cloning and transformation
- • Viral load quantification
- • Gene expression studies
Note: Actual molecular weights may vary slightly based on GC content and modifications.