1. What is the Ligation Calculator?

The Ligation Calculator helps determine the appropriate mass of DNA insert needed for a ligation reaction based on the vector mass, lengths of both fragments, and desired molar ratio.

2. How Does the Calculator Work?

The calculator uses the ligation formula:

Where:

• \( MI \) — Insert mass (ng)
• \( MV \) — Vector mass (ng)
• \( LI \) — Insert length (bp)
• \( LV \) — Vector length (bp)
• \( R \) — Molar ratio (insert:vector)

Explanation: The equation calculates the mass of insert DNA needed to achieve a specific molar ratio with your vector DNA, accounting for their different lengths.

3. Importance of Proper Ligation Ratios

Details: Using the correct insert:vector ratio is crucial for efficient ligation. Typical ratios range from 1:1 to 10:1 (insert:vector), with 3:1 being most common.

4. Using the Calculator

Tips: Enter vector mass in ng, lengths in bp, and desired molar ratio. All values must be positive numbers. The default ratio is set to 3:1.

5. Frequently Asked Questions (FAQ)

Q1: What is the ideal molar ratio for ligation?
A: For most applications, a 3:1 insert:vector ratio works well. You may need to optimize this for difficult ligations.

Q2: How do I measure DNA concentration accurately?
A: Use a spectrophotometer (Nanodrop) or fluorometer (Qubit) for accurate DNA quantification.

Q3: What if my insert is much smaller than my vector?
A: The calculator automatically accounts for size differences - smaller inserts will require less mass to achieve the same molar ratio.

Q4: Can I use this for blunt-end ligations?
A: Yes, but blunt-end ligations typically require higher insert:vector ratios (5:1 to 10:1) due to lower efficiency.

Q5: How does this relate to NEB ligation protocols?
A: This calculator follows the standard NEB ligation calculation method, compatible with their Quick Ligation Kit and T4 DNA Ligase protocols.