1. What is 5-Fold Serial Dilution?

5-fold serial dilution is a laboratory technique where a substance is diluted in a series of steps, with each step being a 1:5 dilution of the previous concentration. This creates a logarithmic series of concentrations useful for various experiments.

2. How Does the Calculator Work?

The calculator uses the serial dilution formula:

Where:

• \( C_n \) — Concentration after n dilutions
• \( C_0 \) — Initial concentration
• \( n \) — Number of dilution steps

Explanation: Each dilution step reduces the concentration by a factor of 5, creating an exponential decrease in concentration.

3. Importance of Serial Dilution

Details: Serial dilutions are essential in microbiology, biochemistry, and pharmacology for creating concentration gradients, determining IC50 values, and preparing standard curves.

4. Using the Calculator

Tips: Enter the initial concentration in mg/mL and the number of dilution steps needed. The calculator will show the concentration at each step.

5. Frequently Asked Questions (FAQ)

Q1: Why use 5-fold instead of 10-fold dilution?
A: 5-fold dilutions provide intermediate concentrations between 10-fold steps, useful when you need finer resolution in your concentration range.

Q2: How do I perform a 5-fold dilution in the lab?
A: Mix 1 part of the stock solution with 4 parts of diluent (e.g., 1 mL stock + 4 mL buffer) for each dilution step.

Q3: What's the maximum number of practical dilutions?
A: Typically 6-8 steps, as further dilutions may reach concentrations below detection limits or become impractical to handle.

Q4: Can I use different dilution factors?
A: Yes, though the calculator is specifically designed for 5-fold dilutions. The principle works for any dilution factor.

Q5: How accurate are these calculations?
A: The calculations are mathematically precise, but actual experimental results depend on pipetting accuracy and solution homogeneity.