Some notes Practice Dilution Practice 1 Scenario: The stock concentration of a mystery substance (MS) is 5 M. Calculate how to dilute to 100 µM (0.1 mM): Use sequential 1:499 and 1:99 dilution steps for accurate preparation. Step 1: Dilute 5 M (5,000,000 µM) to 10,000 µM (500x dilution). Step 2: Dilute 10,000 µM to 100 µM (100x dilution). Dilution Practice 2
Some notes
Practice
Dilution Practice 1
Scenario: The stock concentration of a mystery substance (MS) is 5 M. Calculate how to dilute to 100 µM (0.1 mM): Use sequential 1:499 and 1:99 dilution steps for accurate preparation. Step 1: Dilute 5 M (5,000,000 µM) to 10,000 µM (500x dilution). Step 2: Dilute 10,000 µM to 100 µM (100x dilution).
Dilution Practice 2
The stock concentration of a mystery substance (MS) is 5 M. If the molar mass of MS is 532 g/mol, what’s the concentration of the stock concentration in g/mL? To make your life easier, you can use one of many online calculators. You will perform a serial dilution to get 100 uM of MS. Devise a plan to dilute a 5 M MS solution to 100 uM. How many dilution steps will we need? Which tubes should we use? Which pipettes?
Fill out the following chart to prepare a final reaction with 60 uL reaction volume. Why did we make 100 uM MS if we actually need 40 uM MS? Why not prepare 40 uM in serial dilutions?
Keeping a 100 µM stock as your working standard gives flexibility, longer shelf life, and higher precision for multiple experiments.
