When you're thinking about dilution, it helps to simplify your actions into dilution factors. When we said the diluted coffee was

• Serial Dilution Definition
• Serial Dilution Calculator
• 1:4 Serial Dilution Table

A serial dilution is any dilution in which the concentration decreases by the same factor in each successive step. In serial dilutions, you multiply the dilution factors for each step. The dilution factor or the dilution is the initial volume divided by the final volume. Serial Dilution Calculator This calculator is intended for laboratory scale applications although it can also be used for bigger scale applications as well. A solution of lower concentration is made by diluting a calculated volume of a solution of higher concentration with solvent (most commonly water) up to a specified volume (the volume of. APPENDIX 3 489 TABLE A3.1 Summary of Methods for Preparing a 3-Fold, 2-Fold, and 1.5-Fold Serial Dilution Set for Inhibitor (or Substrate) Titration Dilution.

'1/10th as strong as the original'

that was a dilution factor. We could also have said

'the dilution factor was 1/10', or

'the dilution factor was 0.1'.

Here are a few more for you to try:

1. 1 mL coffee + 4 mL water =
2. 1 mL coffee + 9mL water =
3. 1 mL + 99mL water =

As you've probably guessed, this works exactly the same whether you're talking about caffeine or meningicocci. Here's what a dilution factor of 0.01 looks like on the lab bench:

Notice that it really doesn't matter how much of the original stock you started with, as long as you had enough to put 1 mL into the new container. What matters is how much you transfer and how much water you add.

It's possible to write an algebraic expression for the dilution factor, but it's almost more trouble than it's worth, because it sounds so complex. But for what it's worth, the dilution factor for 1 mL stock + 99 mL water is:

amount transferred / total amount =

amount transferred / (amount transferred + amount water added) =

1 / (1+99) = 1/100 = 0.01.

Below is an applet to practice finding dilution factors, and also to determine how much water to add to achieve a given dilution. You should practice this until it is second nature!!

Can you do it in your sleep? OK, then go on to the next page...

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Serial Dilution Definition

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Knowing how to calculate dilutions is crucial to the safe practice of aromatherapy.

It’s not enough to simply say “dilute before use on the skin”—this is insufficient information. You need to know which dilutions are safe and how to calculate them. With that information, you can use a chart like this to guide accurate dilution.

To avoid the risk of skin allergy:

• Clove bud oil should be used at no more than 0.5%
• Holy Basil oil can be used at up to 1%

To avoid the risk of phototoxicity:

• Lemon oil should be used at no more than 2%
• Grapefruit oil can be used at up to 4%

Serial Dilution Calculator

Essential Calculation Class

1:4 Serial Dilution Table

You love essential oils, and you got hooked into aromatherapy – but nobody told you there will be math. Join Hana Tisserand as she guides you through calculations and conversions with ease, giving you simple tools and making sure you get it, so you will never again have to ask: “How many drops is that?”