1. What is Molarity?

Molarity is a way to measure how concentrated a solution is. It tells us how many moles of a substance are dissolved in one liter of liquid. For DNA solutions, we use molarity to know how many DNA molecules are in our sample.

2. How Does the Calculator Work?

The calculator uses this simple formula:

Where:

• \( M \) — Molarity (moles per liter)
• \( C \) — DNA concentration (nanograms per microliter)
• \( MW \) — Molecular weight (grams per mole)

Explanation: The calculator converts your DNA concentration to molarity by dividing by the molecular weight of your DNA.

3. Why is Molarity Important?

Details: Knowing the molarity of your DNA solution helps in experiments where you need to mix precise amounts of DNA with other chemicals. It's especially important in PCR and other molecular biology techniques.

4. Using the Calculator

Tips:

• Enter your DNA concentration in ng/μL (this is often written on your DNA sample tube)
• Enter the molecular weight of your DNA in g/mol (for a double-stranded DNA, you can calculate this as 660 g/mol per base pair)
• All values must be positive numbers

5. Frequently Asked Questions (FAQ)

Q1: What if I don't know the molecular weight?
A: For double-stranded DNA, you can estimate it as 660 g/mol × number of base pairs. For single-stranded DNA, use 330 g/mol × number of bases.

Q2: Why is molarity better than concentration?
A: Molarity tells you how many molecules are present, which is more useful for chemical reactions than just knowing the weight.

Q3: What are typical molarity values for DNA?
A: Common working concentrations range from 1 nM (0.000001 M) to 100 μM (0.0001 M) depending on the application.

Q4: Can I use this for RNA too?
A: Yes! Just use the correct molecular weight for RNA (about 340 g/mol per base).

Q5: Why is this calculator good for kids?
A: It uses a simplified version of the molarity formula that's easier to understand, with clear explanations and examples.