1. What is Tocris Dilution?

The Tocris dilution calculator helps researchers prepare solutions of precise molarity by diluting stock solutions. The molecular weight option allows conversion between molarity and mass concentration.

2. How Does the Calculator Work?

The calculator uses the dilution formula:

Where:

• \( M1 \) — Initial molarity (mol/L)
• \( V1 \) — Initial volume (L)
• \( V2 \) — Final volume (L)
• \( M2 \) — Final molarity (mol/L)

With Molecular Weight: Concentration in mg/mL = \( M2 \times MW \)

3. Importance of Molecular Weight

Details: Molecular weight allows conversion between molar concentration (moles/L) and mass concentration (mg/mL), which is often needed for practical lab work.

4. Using the Calculator

Tips: Enter the stock solution molarity, volume to be diluted, final desired volume, and optionally the molecular weight to get concentration in mg/mL.

5. Frequently Asked Questions (FAQ)

Q1: Why is molecular weight important?
A: Many protocols specify concentrations in mg/mL, while molarity is needed for stoichiometric calculations. The MW conversion bridges this gap.

Q2: What units should I use?
A: The calculator uses mol/L for molarity and liters for volume, but you can use any consistent units (e.g., mM and mL).

Q3: How precise should my measurements be?
A: Use at least 4 significant figures for molarity and molecular weight for most biological applications.

Q4: Can I use this for serial dilutions?
A: Yes, you can chain calculations by using the output M2 as the new M1 for subsequent dilutions.

Q5: What if my compound is a salt?
A: Use the molecular weight of the actual compound form you're weighing, including any salt or hydrate components.